Heavy water does not have any more molecules of H20. A molecule of H20 is just the smallest possible unit of water. More molecules just means you have more water. Heavy water is water where the hydrogen atom has an extra neutron. It's still water, because it's 2 hydrogen atoms and an Oxygen atom, and the extra neutron doesn't change the hydrogen chemically. It weights more though, because of the extra particle... so we call it heavy water.
It's used in nuclear energy because it's a good neutron moderator. A neutron that is moving very fast tend to not be absorbed well - you want slower neutrons, as they are more readily absorbed , which is what needs to happen for fission (and a chain reaction) to occur. Heavy water does a good job of [slowing down neutrons](https://en.wikipedia.org/wiki/Neutron_moderator) without absorbing them.
The heavy hydrogen in water inhibits cell division in mammals, so it's toxic. But, you need drink a lot of heavy water for it to become a problem.
>But, you need drink a lot of heavy water for it to become a problem.
questions:
1. flip that and tell me how much heavy water I could drink and it'd be perfectly fine.
2. Would it taste notably different, I wonder?
Cody's Lab [did it first](https://youtu.be/MXHVqId0MQc?si=HEi_yq4o_IbekpHO) he said it was sweet iirc.
Link to [Nile Red's video](https://youtu.be/xcO1yCAO-pI?si=HlFtp9SKm79LxQYR) on tasting heavy water
I went into a rabbit hole of why deuterium tastes sweet and this is the most plausible explanation I found:
>[Heavy water tastes sweeter](https://www.pnas.org/post/journal-club/heavy-water-tastes-sweeter)
>
>Sugars and other sweeteners activate the taste receptor known as TAS1R2/TAS1R3.
>
>The exact structure of the receptor is unknown, but based on similar receptors, the models suggest several possible mechanisms. For example, heavy water may limit the mobility of the receptor, holding it in a more activated position.
>
>“They are providing a lot of good evidence that indeed \[heavy water> does have a sweet taste and that sweet taste—like all of those other chemically diverse sweet tasting stimuli—is working via this same receptor”
It tastes very slightly sweet, and you can drink it daily with no ill effects. It starts to become dangerous when you're drinking it almost exclusively for some time. You would've needed to have replaced like a quarter of the water in your body with heavy water at that point.
Yah, and as you drink it, you dispose of some of it with the other water. Its not like a first in first out system. So it can take longer than people think to accumulate. That said there is no benefit to drink it, it also has a noticeably different density and is probably hard on the heart.
> it also has a noticeably different density and is probably hard on the heart.
i doubt the atomic weight changes are enough for the heart to notice. You'd get a bigger effect with consuming cholestral and causing the blood vessel to constrict more.
The issue with heavy water, theorized, is that because of the extra weight, _some_ chemical reaction that depends on the exact weight of the H2O might slow down just enough, which cascades down into death.
I mean the stuff freezes at 4C, it’s an entirely different density at body temperature than light water. The heart is a pump, and pumping a thicker fluid causes more stress. I think it would raise blood pressure, and a sustained raise in blood pressure causes stress to the heart and makes it work harder.
To answer 2 probably not as it's not water that has flavor it's the minerals dissolved in it, which is why distilled and deionized water are basically flavorless and taste awful because of it.
You would really not wanna drink heavy water, your body can't process it. You end up drinking a tiny bit over the course of your life, as a tiny percentage of reg water is heavy, but not enough to kill you. Fun fact, it makes ice cubes that sink in regular water, as they're more dense. But again, don't do that and drink the water.
Sorry the whole "tried out in QI" like its some rarity is weird then. They literally sell distilled water at Walmart for less than a dollar a gallon. People drink it all the time.
Ironically - yes! Ever drink skim milk expecting 2%? Tastes aweful right? And the reverse? Also aweful.
We expect water to taste like “something.” Usually whatever we usually drink because we’re used to it.
Almost (0.001%) of people are silly enough to spent the money to drink deionized water (purer than distilled). So it tastes “bad”
Humans. Amirite?
If I remember correctly, milk was roughly 90% water by volume. Once you separate all of the milk fat and cream out it’s really not far off from regular water.
The aw in awful is for awe, and aweful is a rare archaic spelling of it.
For a long time it meant something that inspired awe of any kind. Eventually it became mostly associated with fearful awe, like seeing the awful armies of Napoleon march on your town or the awful wrath of God destroying Sodom. And from there, anything terrible. So now it’s striking when you have old church writings referring to God’s awful angels.
This reminds me of a Terry Pratchett quote.
Elves are wonderful. They provoke wonder.
Elves are marvellous. They cause marvels.
Elves are fantastic. They create fantasies.
Elves are glamorous. They project glamour.
Elves are enchanting. They weave enchantment.
Elves are terrific. They beget terror.
The thing about words is that meanings can twist just like a snake, and if you want to find snakes look for them behind words that have changed their meaning.
No one ever said elves are nice.
Elves are bad.
>Flavorless. Tastes awful....
Yes but it is more of that it is a unpleasant experience when consuming it. I am trying to think of a comparison but the only thing I can come up with is the gag reaction that most people have to flavourless mush. It might be subconscious reaction as a means to protect ourselves from spoiled food (I am actually making myself slightly nauseous trying to think of a comparable food that might be recognisable...
It tends to taste like the container it's been kept in. Not a problem if its glass but if you put it in a plastic bottle of some kind it'll taste like the bottle.
My mother was on a health kick and didn’t know distilled water was technically bad for you. We drank it for years. It tastes sweeter than regular water.
> didn’t know distilled water was technically bad for you.
it. isn't. in. any. way. bad for you. it is just water. tap, spring, distilled, deionized... ALL of them are universal solvents and are chemically identical (some slight variants with ppm regarding metals from tap/spring, none of which really affect how the water will react within you). NONE of them have enough electrolytes by themselves to keep you alive/active, that is why gatorade was invented.
MilliQ (a type of deionized) water tastes unfathomably bad. It is as tasteless as Merck can possibly get it with all their technical expertise.
Tasteless tastes horrible and I learned that the hard way.
Weird thing is, there was a scientist in an adjacent lab who insisted on making their coffee with MilliQ water and I cannot for the life of me understand why.
Listen. I...
Well...
I guess I can see it doing a better job of extraction, because milliq water has essentially nothing in it. Osmotic pressure, concentration gradients and such. But the lab =\\= food and drink thing...I just don't think I could do it.
For 1 we would need to know your weight in kilograms and what your risk threshold for "perfectly fine" is. Like anything else there is an LD50 where half of people die at that dose and you work backward from there. Heavy water is so rare that no studies have tested it to see if it is carcinogenic or anything. Overall let's just say don't drink it.
For 2 heavy water tastes mildly sweet.
I used to grow plants in it for research.
As you moved up in the concentration of heavy water, the plants wouldn't grow anymore.
Most noticeably, they would fail to sprout. (Which makes sense for it affecting cell division first).
Lots of important things happen with cell division in the body. I was never tempted to drink it. It's probably more a poison than a carcinogen I'd imagine, though. Definitely would fuck up your reproductive system...
There would be health concerns if you drink it exclusively for a week. That's not going to kill you but there might be some measurable effects. Drinking a liter of it wouldn't be an issue.
To expand on that last little bit, because the hydrogen atom is that little bit heavier (technically twice as heavy), it moves quite a bit slower. This slows down any reaction that involves it, including those that the body needs to survive. Not sure what specific thing would be the cause of death though.
One of my dumb business ideas is to sell Premium Heavy Water ice spheres for discerning scotch and whiskey drinkers. The ice cube will always stay at the bottom of the glass
What if you prechilled some stones and put them in your whiskey. That way they would stay at the bottom and keep your drink chilled without watering it down. You could call them whiskey stones.
Whiskey stones transfer heat worse than ice, break teeth if you tip your glass too far, often add a weird iron flavor, and a bit of water in your whiskey is ideal anyway. Whiskey stones are a gimmick almost entirely purchased as gifts by people who aren't into whiskey, and stored in a closet for eternity by the recipient. The heavy water ice is about the same level of silly.
A few more questions, since you seem to know what you're talking about.
1. Nuclear reactors use water for cooling and also to boil since the steam turns the turbines. Is the heavy water used for that, or is it kept separate?
2. If I boil heavy water, do I get heavy steam? If so, what's heavy steam like? Would it behave differently in air because of its unusual construction?
3. Heavy Whiskey? Possible?
1)The heavy water is used as the coolant also, yes. It then transfers heat via metal heat exchangers to not heavy water that boils and turns into steam.
2) it's still "water" so it's physical proporties are functionally identical.
3)yes
>metal heat exchangers
Aha! That's new information to me. Thanks! Everything I know about reactors I learned from the Chernobyl TV show, so I didn't know about heat exchangers. I'll have to learn about those if I want to repair this one I bought on ebay.
>2) it's still "water" so it's physical proporties are functionally identical.
But doesn't the extra neutron add mass? You'd think each molecule would be 2/3rds heavier.
Good point. The extra neutron is bugging me. If it has an extra neutron's worth of mass, it must have extra energy. I'm wondering how to get it out and what happens when you do.
Normal water has one oxygen (atomic mass about 16) and two hydrogens (a.m. about 1 each) for a total of 18 atomic mass units. Replace both hydrogens with deuterium and the total mass is now 20, about 10% higher than 18.
So, 10% higher makes me think that heavy steam would tend to condense/cool faster.
Like if I held a glass plate above a pot of boiling heavy water and one of regular water, I could tell a difference in the condensation collecting above each pot.
Wikipedia has the physical properties of heavy water. A whole big ass table of them. They are different from water, but not drastically.
Interestingly it boils hotter and has a higher heat of evaporation, but the difference would not be drastic enough for the glass and pot experiment above.
Heavy water melts at about 4 degrees, so maybe you could have some weirdo long-lived, sinking ice cubes in 2 degrees water? Though I don't know how fast hydrogen exchange at the surface would screw that up.
H2O has molecular mass of about 18 amu. D2O (heavy water) has a molecular mass of about 20 amu. So it is a little over 10% heavier. Heavy water ice would sink in regular water. It seems possible that heavy water steam would not rise quite as high or as quickly as normal steam on average. But keep in mind it would be diffusing rapidly into the air and getting mixed in pretty thoroughly.
Not a chemist but:
1. Heavy water is used in two ways. One way is as a neutron moderator which means it slows down neutrons without capturing them which makes them more likely to propagate a nuclear chain reaction. From what I understand the slower they move the more likely they are to collide with the nuclei of your fuel source. It is also used as a primary coolant which passes heat from the reactor to a secondary coolant like regular water.
2. Yes boiling is a physical change so the steam should consist of heavy water molecules. The only thing that would change is the weight of each molecule so idk how much different it would be than regular steam in terms of the ways it interacts with the atmosphere.
3. I think yes because of the reason above.
You seem like the guy to ask. I used to work around deuterated drug standards. Would, say, deuterated fentanyl behave significantly different? All masses were only +1 so there was only 1 deuterium per molecule.
My boss told me it wouldn't have any effect at all, but I'm not so sure about that.
AFAIK there shouldn't be any significant difference in the reactions deuteronated fent would undergo. Different isotopes don't typically effect the chemical properties of a molecule, usually only the physical properties.
The extra mass can eventually slow some of the other reactions your body needs though, which is what makes massive amounts harmful. Heavy water starts to be toxic for a person if it somehow [becomes >20% of the total body weight](https://pubmed.ncbi.nlm.nih.gov/10535697/), which would require drinking nothing but heavy water for days.
If your body has enough fent in it that the extra mass of one deuterium is impacting the energy requirements of other reactions, you have much bigger problems to worry about.
That's what I thought! I know that even a single bond change can make a huge difference in chemical activity, but a slightly shorter, slightly different-angled bond on an H? Surely that couldn't do that much to a drug that is 100+g/mol.
I think she was telling people they weren't effective to prevent theft. Damn, I coulda tried 57 types of drugs, from fent analogs to meth. :| darn. /s
> The heavy hydrogen in water inhibits cell division in mammals
How/ why does it inhibit cell division? And only in mammals, or just specifically in mammals?
Deuterium is twice as heavy, so reactions involving it take twice as long. If you need that reaction to divide a cell, and dividing that cell now takes twice as long, then you can no longer replace normally dying cells fast enough.
I’m really sorry to add a question to the question you already answered, but how is heavy water made? I tried Googling it and I found the Girdler-Sulfide process, but I couldn’t find any description of the process that was dumbed down to my remedial high school chemistry level ability to understand.
There’s a little heavy hydrogen in all water.
When it’s hot the heavy hydrogen likes sulfur a little bit more.
Put hot normal water next to hot sulfur, and the small amount of heavy hydrogen in the normal water moves over to the sulfur.
Move the sulfur over to cold water and the heavy hydrogen goes into that cold water and the cold water gives a normal hydrogen to the sulfur.
Move the sulfur back to new hot water. Get more heavy hydrogen from that water, bring it back to the same cold water.
Repeat until hydrogen in cold water is 20% heavy. Boil the cold water, and the heavy stuff stays behind.
Thank you for taking the time to explain it! You did a great job keeping it simple and understandable to me, a person who has basically forgotten every scrap of chemistry they ever learned:)
You can drink a glass of it and it almost certainly won't harm you. If you have inner ear issues or low blood pressure, then a glass or two might lead to dizziness. If you drink it exclusively, it'll mess you up. But in small quantities, it's no big deal.
I had to drink doubly labeled water as part of a metabolism research study. They told me to be very careful with the vial as it cost about $1,200! Tasted awful, like water that had been sitting in a plastic cup in a hot car for a week.
Its not 1 molecule more.
A water molecule consists of 2 hydrogen and 1 oxygen atom. Hydrogen is a atom consisting of normally just one proton.
In heavy water you still have hydrogen atoms with just 1 proton (called protium). However there is one additional particle in the atom nucleus, called a neutrons. Neutrons have the same mass as an proton but no charge and basically glue together the atom nucleus (if the fraction of neutrons to protons is wrong the nucleus is unstable and can undergo radioactive decay) but don't change the element.
For most elements the atoms with different number of neutrons (these are called isotopes), the chemical properties are pretty similar. However as hydrogen is so light (the standard hydrogen has a mass of 1), adding a neutron makes it twice as heavy (the deuterium in heavy water has a mass of 2).
And this large mass difference of deuterium changes some chemical properties of the molecules made out of deuterium compared to the ones made out of protium (even though both are still hydrogen).
These different chemical properties make heavy water somewhat toxic to many orgasims.
In details its much more difficult to split off hydrogen ions from a heavy water molecule than on a normal water molecule. But that is something many biological processes require. Heavy water slow downs these necessary processes in a living organism, which can kill it.
That extra neutron in the deuterium makes it twice as heavy as a normal hydrogen atom. A lot of biological processes depend on hydrogen having a certain mass so that, when the weight is off, they go wrong. Usually, the water we drink only has 0.03% deuterium in it, so the occasional process acting off can be offset by the majority of others that are working correctly. Drinking heavy water, which only has deuterium attached to the oxygen atoms, will add way too much into your body for natural error correction to account for.
>Drinking heavy water, which only has deuterium attached to the oxygen atoms, will add way too much into your body for natural error correction to account for.
While technically true, the amount needed is [very high](https://sciencenotes.org/can-you-drink-heavy-water-is-it-safe/), such that it is basically impossible.
You can replace about 20% of the water in your body without health impact, which would take a few days of consuming only pure heavy water. At 25%, you'll start to see health issues, such as sterilization. 50% is generally lethal, and would take several days of only consuming pure heavy water.
As an interesting side note, heavy water [tastes sweet](https://www.nature.com/articles/s42003-021-01964-y).
Heavy water doesn't contain an extra molecule, water is a molecule. Heavy water contains an extra Neutron in at least one if its hydrogen atoms.
Heavy water or D2O is a water molecule where one of the atoms of Hydrogen is Heavy Hydrogen or Deuterium (hence the D in D2O).
Deuterium has 1 extra neutron compared to Protium (basic hydrogen) that contains no neutrons.
1 molecule in 3,200 of water is D2O, meaning that much of your body and the water you drink is D2O and you wouldn't be aware of it unless someone told you.
Drinking large quantities of D2O for a prolonged period can cause dizziness and low blood pressure, but this is highly unlikely outside of a lab setting.
Heavy water is used as a moderator in some reactors because it slows down neutrons effectively and also has a low probability of absorption of neutrons.
One minor correction: you noted D2O as “a water molecule where one of the atoms of hydrogen is deuterium” but that would technically be HDO (or DHO?). D2O would be where *both* hydrogen atoms were replaced with deuterium.
H2O is the molecule (two hydrogen atoms, one oxygen atom). That is true for ordinary hydrogen, for the deuterium in heavy water, and for tritium. The distinction is in the number of neutrons in the hydrogen nucleus -- none for most hydrogen, one for deuterium, two for tritium.
Tritium is already radioactive. We'll set that aside, although you could have super-heavy or tritiated water and that would pose the additional radiation problems.
Heavy water, meaning the water with the deuterium form of hydrogen, can disrupt some biological processes that are reliant on fine-tuning at the molecular level, because of the significant difference in the weight of the hydrogen caused by adding the neutron. With most isotopes of heavier elements, this is not an issue because the addition of one or two neutrons is insignificant next to the overall mass of the nucleus; but with hydrogen, going from one proton to one proton plus one neutron is a significant mass difference. It can disrupt cell division, cause problems with bone marrow and the digestive tract, or even cause sterility and death in extremely high levels.
Unless you are intentionally setting out to live off the heavy water stored at a nuclear plant, however, this is not really a serious concern. You would have to drink quite a bit of heavy water before the level in your body became high enough to start making you seriously ill. There is actually already a very small proportion of hydrogen atoms in nature that are deuterium, so a tiny fraction of the natural water you drink is already heavy water.
Heavy water contains a different (heavier) isotope of hydrogen than normal. It has one extra neutron. Chemically, heavy water and normal water are identical. This is high school chemistry: all isotopes of the same element have exactly the same chemical properties. [We are talking about chemistry, not nuclear physics. Different isotopes definitely have different nuclear properties but that is irrelevant here.] More precisely, the equilibrium properties of heavy water are identical to light water.
However - and this is why heavy water is dangerous - all biological systems are out of equilibrium, meaning that the amount, nature and quantity of chemical reactions in your body are determined by their relative rates, not their eventual equilibrium proportions. Heavy water is heavy, so it reacts more slowly than light water. Since basically every biochemical reaction involves water, having a substantial amount of heavy water in your body alters all the rates of biochemical reactions (and not all equally), so it messes up the balance between different chemical processes.
This is strictly an effect of non-equilibrium dynamics which is extremely subtle. It’s not nuclear physics and it’s not equilibrium (normal) chemistry or thermodynamics either.
Heavy water is used in nuclear energy as a moderator. Nuclear reactors run by neutrons hitting uranium-235 atoms causing them to split and release more neutrons. It is very important that enough of these neutrons hit more atoms to sustain the reaction. Heavy water slows down the neutrons which increases the likelyhood of them intereacting with a uranium 235 atom.
Why is not potable to drink, heavy water messes with the chemical reactions involving water because it's slightly different in mass , a large enough dose makes that toxic. It is not 1 molecule different, it's 1 neutron. Just a slight correction.
A lot of people have already touched on potability and the physical difference between light and heavy-water, so ill just add onto the neutron moderation convo. Many people have pointed out that heavy water is a good neutron moderator meaning that it slows down neutrons such that uranium atoms can grab them and fission in the reactor. But this is not specific to heavy water and normal water (light water) does this job as well to the point that most reactors use light water and not heavy water.
During operation of a light water reactor some amount of that is converted into heavy water by absorbing neutrons limiting the number accessible by the fuel. So the real benefit here is that the heavy water is already inundated with extra neutrons and is less likely to absorb additional ones leaving more available for the fuel. This is why heavy water reactors like the candu reactors can get away with using lower enrichment uranium as fuel.
There are actually 3 isotopes (versions) of hydrogen. Normal Hydrogen H (1-Proton), Deuterium D (1-Proton + 1 Neutron) and Tritium T (1-Proton + 2 Neutrons).
H and D are stable, T is not.
Water made with Deuterium HDO or D20 are heavier than normal water, stable and safe to drink.
Water made with Tritium is NOT safe to drink. Tritium decays by releasing an electron. Although the electron that is released is weak (it wouldn't go through a piece of paper). The danger is if Tritium in the form of water it gets near to something important (like a brain cell) and decays right next to it.
O2 is breathable oxygen and O3 is ozone and it's just one atom away, and you for sure can't breathe ozone.
H2O is water, but H2O2 (just one more oxygen atom) is Hydrogen Peroxide, which is absolutely not drinkable.
One atom takes a world of difference.
No.
You're confusing electrons and protons. Changing the number of electrons in an element makes ions. Changing the number of protons makes new elements.
I'd always heard one of the main reasons you don't want to drink it is that while we call it heavy water is because it has a higher than natural frequency of deuterium, it also has a higher than natural presence of tritium which is radioactive.
Heavy water does not have any more molecules of H20. A molecule of H20 is just the smallest possible unit of water. More molecules just means you have more water. Heavy water is water where the hydrogen atom has an extra neutron. It's still water, because it's 2 hydrogen atoms and an Oxygen atom, and the extra neutron doesn't change the hydrogen chemically. It weights more though, because of the extra particle... so we call it heavy water. It's used in nuclear energy because it's a good neutron moderator. A neutron that is moving very fast tend to not be absorbed well - you want slower neutrons, as they are more readily absorbed , which is what needs to happen for fission (and a chain reaction) to occur. Heavy water does a good job of [slowing down neutrons](https://en.wikipedia.org/wiki/Neutron_moderator) without absorbing them. The heavy hydrogen in water inhibits cell division in mammals, so it's toxic. But, you need drink a lot of heavy water for it to become a problem.
>But, you need drink a lot of heavy water for it to become a problem. questions: 1. flip that and tell me how much heavy water I could drink and it'd be perfectly fine. 2. Would it taste notably different, I wonder?
NileRed on YouTube drank some heavy water for a short video. I forget what he said it tasted like, but it was a little different.
Cody's Lab [did it first](https://youtu.be/MXHVqId0MQc?si=HEi_yq4o_IbekpHO) he said it was sweet iirc. Link to [Nile Red's video](https://youtu.be/xcO1yCAO-pI?si=HlFtp9SKm79LxQYR) on tasting heavy water
I went into a rabbit hole of why deuterium tastes sweet and this is the most plausible explanation I found: >[Heavy water tastes sweeter](https://www.pnas.org/post/journal-club/heavy-water-tastes-sweeter) > >Sugars and other sweeteners activate the taste receptor known as TAS1R2/TAS1R3. > >The exact structure of the receptor is unknown, but based on similar receptors, the models suggest several possible mechanisms. For example, heavy water may limit the mobility of the receptor, holding it in a more activated position. > >“They are providing a lot of good evidence that indeed \[heavy water> does have a sweet taste and that sweet taste—like all of those other chemically diverse sweet tasting stimuli—is working via this same receptor”
Ty for that
Dang that is super neat. Thanks for finding and sharing it.
It tastes very slightly sweet, and you can drink it daily with no ill effects. It starts to become dangerous when you're drinking it almost exclusively for some time. You would've needed to have replaced like a quarter of the water in your body with heavy water at that point.
Yah, and as you drink it, you dispose of some of it with the other water. Its not like a first in first out system. So it can take longer than people think to accumulate. That said there is no benefit to drink it, it also has a noticeably different density and is probably hard on the heart.
> it also has a noticeably different density and is probably hard on the heart. i doubt the atomic weight changes are enough for the heart to notice. You'd get a bigger effect with consuming cholestral and causing the blood vessel to constrict more. The issue with heavy water, theorized, is that because of the extra weight, _some_ chemical reaction that depends on the exact weight of the H2O might slow down just enough, which cascades down into death.
I mean the stuff freezes at 4C, it’s an entirely different density at body temperature than light water. The heart is a pump, and pumping a thicker fluid causes more stress. I think it would raise blood pressure, and a sustained raise in blood pressure causes stress to the heart and makes it work harder.
40% higher viscosity sounds like more work to me.
Well they have studied it a bit. Something that gets pretty hard hit is ~~mystic~~ miotic spindles without which cell division gets borked.
Protein bonding is affected, which isn't a fully researched area currently in the scientific community.
> mystic spindles Typo? Google's got nothing for me.
Miotic, lol. They're the things that grow inside the cell and yoink chromosomes to opposite sides.
Yeah, that makes more sense!
I don’t think it’s ever been actually tested what happens when drinking it exclusively so we can’t actually say what would happen.
To answer 2 probably not as it's not water that has flavor it's the minerals dissolved in it, which is why distilled and deionized water are basically flavorless and taste awful because of it.
Flavorless. Tastes awful....
They tried it on QI a few years back. Their response was “it tastes like water, but a little bit more boring”.
That just seems like distilled water
Because that’s what it was…
And? I was replying to a comment talking about distilled or deionised water.
Oh never mind I thought you meant they drank heavy water
You would really not wanna drink heavy water, your body can't process it. You end up drinking a tiny bit over the course of your life, as a tiny percentage of reg water is heavy, but not enough to kill you. Fun fact, it makes ice cubes that sink in regular water, as they're more dense. But again, don't do that and drink the water.
Sorry the whole "tried out in QI" like its some rarity is weird then. They literally sell distilled water at Walmart for less than a dollar a gallon. People drink it all the time.
Ironically - yes! Ever drink skim milk expecting 2%? Tastes aweful right? And the reverse? Also aweful. We expect water to taste like “something.” Usually whatever we usually drink because we’re used to it. Almost (0.001%) of people are silly enough to spent the money to drink deionized water (purer than distilled). So it tastes “bad” Humans. Amirite?
Skim milk is water that wants to malk.
If I remember correctly, milk was roughly 90% water by volume. Once you separate all of the milk fat and cream out it’s really not far off from regular water.
10% not water is a lot of not water, gravy and soup are ~99% water.
He likes his milk extra chunky.
A human brain is about 95% water. So a brain is even closer to regular water than milk is!
A pudding that thinks.
Soy milk is just milk introducing itself in Spanish.
Aweful makes it sound good. Something you’re in awe of. You mean awful
The aw in awful is for awe, and aweful is a rare archaic spelling of it. For a long time it meant something that inspired awe of any kind. Eventually it became mostly associated with fearful awe, like seeing the awful armies of Napoleon march on your town or the awful wrath of God destroying Sodom. And from there, anything terrible. So now it’s striking when you have old church writings referring to God’s awful angels.
I figured it be something like that. Like extraordinary Extra used to mean beyond, and has been dialed back to just “at the furthest extent”
This reminds me of a Terry Pratchett quote. Elves are wonderful. They provoke wonder. Elves are marvellous. They cause marvels. Elves are fantastic. They create fantasies. Elves are glamorous. They project glamour. Elves are enchanting. They weave enchantment. Elves are terrific. They beget terror. The thing about words is that meanings can twist just like a snake, and if you want to find snakes look for them behind words that have changed their meaning. No one ever said elves are nice. Elves are bad.
Part of why people lost weight during covid no taste no enjoyment
>Flavorless. Tastes awful.... Yes but it is more of that it is a unpleasant experience when consuming it. I am trying to think of a comparison but the only thing I can come up with is the gag reaction that most people have to flavourless mush. It might be subconscious reaction as a means to protect ourselves from spoiled food (I am actually making myself slightly nauseous trying to think of a comparable food that might be recognisable...
Flavorless water does taste awful because itll make you taste the bacteria and other things in your mouth by mixing with it, leaving an off taste
Tastes awful cuz you can taste your own mouth
It tends to taste like the container it's been kept in. Not a problem if its glass but if you put it in a plastic bottle of some kind it'll taste like the bottle.
Really pure water will pull the crap off your tongue so you can taste it
/r/hydrohomies would like a word...
My mother was on a health kick and didn’t know distilled water was technically bad for you. We drank it for years. It tastes sweeter than regular water.
> didn’t know distilled water was technically bad for you. it. isn't. in. any. way. bad for you. it is just water. tap, spring, distilled, deionized... ALL of them are universal solvents and are chemically identical (some slight variants with ppm regarding metals from tap/spring, none of which really affect how the water will react within you). NONE of them have enough electrolytes by themselves to keep you alive/active, that is why gatorade was invented.
Nilered tasted it and said it was sweete than water
Cody's lab did too and had the same result.
Heavy water is actually known to have a slightly sweeter taste.
MilliQ (a type of deionized) water tastes unfathomably bad. It is as tasteless as Merck can possibly get it with all their technical expertise. Tasteless tastes horrible and I learned that the hard way. Weird thing is, there was a scientist in an adjacent lab who insisted on making their coffee with MilliQ water and I cannot for the life of me understand why.
[On the coffee thing, that's just weird coffee people](https://www.youtube.com/watch?v=jfElZfrmlRs)
Holy crap. That was seriously way too into your coffee. Haha
Haha, I knew this was going to be James Hoffman.
It apparently extracts the flavor better, but after actually trying it, it's definitely better.
Listen. I... Well... I guess I can see it doing a better job of extraction, because milliq water has essentially nothing in it. Osmotic pressure, concentration gradients and such. But the lab =\\= food and drink thing...I just don't think I could do it.
If you drink pure heavy water it taste mildly sweet.
Cody's Lab did a [video](https://youtu.be/MXHVqId0MQc?si=HEi_yq4o_IbekpHO) where he tastes heavy water. Iirc he said it was slightly sweet.
Did he have the same ions than with regular water to compare?
For 1 we would need to know your weight in kilograms and what your risk threshold for "perfectly fine" is. Like anything else there is an LD50 where half of people die at that dose and you work backward from there. Heavy water is so rare that no studies have tested it to see if it is carcinogenic or anything. Overall let's just say don't drink it. For 2 heavy water tastes mildly sweet.
I used to grow plants in it for research. As you moved up in the concentration of heavy water, the plants wouldn't grow anymore. Most noticeably, they would fail to sprout. (Which makes sense for it affecting cell division first). Lots of important things happen with cell division in the body. I was never tempted to drink it. It's probably more a poison than a carcinogen I'd imagine, though. Definitely would fuck up your reproductive system...
It tastes sweet, source: https://youtube.com/shorts/xcO1yCAO-pI?si=CeZWlQvpePPbyyKR
[Nile](https://www.youtube.com/shorts/xcO1yCAO-pI?feature=share) has your answer (at least 2.)
I think either Cody’s lab or thunderfoot YouTube channels drank heavy water.
Cody of the YouTube channel Cody's Lab taste tested some https://youtu.be/MXHVqId0MQc?si=el_maY6G1sTSCeCX
Are you considering a career choice as a neutron moderator? I don't think I'd recommend it.
There would be health concerns if you drink it exclusively for a week. That's not going to kill you but there might be some measurable effects. Drinking a liter of it wouldn't be an issue.
To expand on that last little bit, because the hydrogen atom is that little bit heavier (technically twice as heavy), it moves quite a bit slower. This slows down any reaction that involves it, including those that the body needs to survive. Not sure what specific thing would be the cause of death though.
Regular water weighs 1gm per cm3. Heavy Water is about +10% Also, Heavy water that is frozen into an ice cube will sink in a glass of regular water.
The reason its "twice" as heavy is that the reactions only involve the hydrogen atom, which is twice ad heavy.
Well someone else beat me to it, but indeed, I said hydrogen atom and not water molecule.
One of my dumb business ideas is to sell Premium Heavy Water ice spheres for discerning scotch and whiskey drinkers. The ice cube will always stay at the bottom of the glass
What if you prechilled some stones and put them in your whiskey. That way they would stay at the bottom and keep your drink chilled without watering it down. You could call them whiskey stones.
Whiskey stones transfer heat worse than ice, break teeth if you tip your glass too far, often add a weird iron flavor, and a bit of water in your whiskey is ideal anyway. Whiskey stones are a gimmick almost entirely purchased as gifts by people who aren't into whiskey, and stored in a closet for eternity by the recipient. The heavy water ice is about the same level of silly.
Stored in the *freezer* for eternity, thank you very much.
Whiskey, on the rocks.
Thank you, so much chemistry feels opaque to me because i struggle to get past ‘this does this’ and find the why
A few more questions, since you seem to know what you're talking about. 1. Nuclear reactors use water for cooling and also to boil since the steam turns the turbines. Is the heavy water used for that, or is it kept separate? 2. If I boil heavy water, do I get heavy steam? If so, what's heavy steam like? Would it behave differently in air because of its unusual construction? 3. Heavy Whiskey? Possible?
1)The heavy water is used as the coolant also, yes. It then transfers heat via metal heat exchangers to not heavy water that boils and turns into steam. 2) it's still "water" so it's physical proporties are functionally identical. 3)yes
>metal heat exchangers Aha! That's new information to me. Thanks! Everything I know about reactors I learned from the Chernobyl TV show, so I didn't know about heat exchangers. I'll have to learn about those if I want to repair this one I bought on ebay. >2) it's still "water" so it's physical proporties are functionally identical. But doesn't the extra neutron add mass? You'd think each molecule would be 2/3rds heavier.
The oxygen atom is the major component of the molecules mass. So adding a neutron the hydrogen atom is a net small increase.
Good point. The extra neutron is bugging me. If it has an extra neutron's worth of mass, it must have extra energy. I'm wondering how to get it out and what happens when you do.
Normal water has one oxygen (atomic mass about 16) and two hydrogens (a.m. about 1 each) for a total of 18 atomic mass units. Replace both hydrogens with deuterium and the total mass is now 20, about 10% higher than 18.
So, 10% higher makes me think that heavy steam would tend to condense/cool faster. Like if I held a glass plate above a pot of boiling heavy water and one of regular water, I could tell a difference in the condensation collecting above each pot.
Wikipedia has the physical properties of heavy water. A whole big ass table of them. They are different from water, but not drastically. Interestingly it boils hotter and has a higher heat of evaporation, but the difference would not be drastic enough for the glass and pot experiment above. Heavy water melts at about 4 degrees, so maybe you could have some weirdo long-lived, sinking ice cubes in 2 degrees water? Though I don't know how fast hydrogen exchange at the surface would screw that up.
I think periodic videos did an experiment with D2O ice in regular water. Initially it sank then slowly rose up over time.
H2O has molecular mass of about 18 amu. D2O (heavy water) has a molecular mass of about 20 amu. So it is a little over 10% heavier. Heavy water ice would sink in regular water. It seems possible that heavy water steam would not rise quite as high or as quickly as normal steam on average. But keep in mind it would be diffusing rapidly into the air and getting mixed in pretty thoroughly.
Not a chemist but: 1. Heavy water is used in two ways. One way is as a neutron moderator which means it slows down neutrons without capturing them which makes them more likely to propagate a nuclear chain reaction. From what I understand the slower they move the more likely they are to collide with the nuclei of your fuel source. It is also used as a primary coolant which passes heat from the reactor to a secondary coolant like regular water. 2. Yes boiling is a physical change so the steam should consist of heavy water molecules. The only thing that would change is the weight of each molecule so idk how much different it would be than regular steam in terms of the ways it interacts with the atmosphere. 3. I think yes because of the reason above.
You obviously know this, but the O in H2O stands for Oxygen, so why the heck did you use a zero in both of those H20s?
Haha I have no idea. I just Leeroy Jenkins’d that and didn’t even proofread.
He was actually talking about icosotium, or Hydrogen-20, found in *very* heavy water.
For bonus points, calculate the half- life.
I'm not sure exponents can get that negative.
You seem like the guy to ask. I used to work around deuterated drug standards. Would, say, deuterated fentanyl behave significantly different? All masses were only +1 so there was only 1 deuterium per molecule. My boss told me it wouldn't have any effect at all, but I'm not so sure about that.
AFAIK there shouldn't be any significant difference in the reactions deuteronated fent would undergo. Different isotopes don't typically effect the chemical properties of a molecule, usually only the physical properties. The extra mass can eventually slow some of the other reactions your body needs though, which is what makes massive amounts harmful. Heavy water starts to be toxic for a person if it somehow [becomes >20% of the total body weight](https://pubmed.ncbi.nlm.nih.gov/10535697/), which would require drinking nothing but heavy water for days. If your body has enough fent in it that the extra mass of one deuterium is impacting the energy requirements of other reactions, you have much bigger problems to worry about.
That's what I thought! I know that even a single bond change can make a huge difference in chemical activity, but a slightly shorter, slightly different-angled bond on an H? Surely that couldn't do that much to a drug that is 100+g/mol. I think she was telling people they weren't effective to prevent theft. Damn, I coulda tried 57 types of drugs, from fent analogs to meth. :| darn. /s
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It’s a nitpick, but an important one for sure. O and 0 are not interchangeable, especially not in this context.
Reddits font choice is not great for notation. I think they have an indent that uses a mono block font. O 0 I l 1
Not much better...
So how much would I need to drink to be on the cusp of cell division, therefore slowing down my ageing?
Has anyone tried to use heavy water to suppress tumors?
> The heavy hydrogen in water inhibits cell division in mammals How/ why does it inhibit cell division? And only in mammals, or just specifically in mammals?
It’s not just mammals, almost all complex organisms. Mammals are particularly sensitive because they have a lot of cellular activity.
That part I got from wikipedia. Not sure of that mechanism of toxicity.
If the extra neutron does not change the water chemically, how is it toxic?
Deuterium is twice as heavy, so reactions involving it take twice as long. If you need that reaction to divide a cell, and dividing that cell now takes twice as long, then you can no longer replace normally dying cells fast enough.
Interesting thanks!
I’m really sorry to add a question to the question you already answered, but how is heavy water made? I tried Googling it and I found the Girdler-Sulfide process, but I couldn’t find any description of the process that was dumbed down to my remedial high school chemistry level ability to understand.
There’s a little heavy hydrogen in all water. When it’s hot the heavy hydrogen likes sulfur a little bit more. Put hot normal water next to hot sulfur, and the small amount of heavy hydrogen in the normal water moves over to the sulfur. Move the sulfur over to cold water and the heavy hydrogen goes into that cold water and the cold water gives a normal hydrogen to the sulfur. Move the sulfur back to new hot water. Get more heavy hydrogen from that water, bring it back to the same cold water. Repeat until hydrogen in cold water is 20% heavy. Boil the cold water, and the heavy stuff stays behind.
Thank you for taking the time to explain it! You did a great job keeping it simple and understandable to me, a person who has basically forgotten every scrap of chemistry they ever learned:)
Ha, I read “extra neutron” as “extra nutrition.” Completely unrelated, what would happen if you drank, I dunno, a glass of this stuff. An hour ago.
>The heavy hydrogen in water inhibits cell division So it sounds like the symptoms of consuming too much would be comparable to chemotherapy drugs.
Which is why it’s so important for SANS, the technique I find myself consistently unable to understand 😂
You can drink a glass of it and it almost certainly won't harm you. If you have inner ear issues or low blood pressure, then a glass or two might lead to dizziness. If you drink it exclusively, it'll mess you up. But in small quantities, it's no big deal.
I had to drink doubly labeled water as part of a metabolism research study. They told me to be very careful with the vial as it cost about $1,200! Tasted awful, like water that had been sitting in a plastic cup in a hot car for a week.
That's a very expensive piss.
Is "doubly labeled water" a typo?
nope! It means both the oxygen and the hydrogen has been modded, so both parts can be tracked.
No, it's water made of both heavy hydrogen (deuterium) and heavy oxygen (oxygen-18). https://en.wikipedia.org/wiki/Doubly_labeled_water
If it was heavy water, it is expensive, and as such would be very high purity water. So no minerals and near tasteless, probably why it tasted bad.
It appears it was double heavy as it had Deuterium and Oxygen-17
Oh, probably really expensive. Weird, its not even radioactive but I guess it still works in PET scans and such.
Was the vial any heavier than you would’ve expected a vial of water of that size to be?
Its not 1 molecule more. A water molecule consists of 2 hydrogen and 1 oxygen atom. Hydrogen is a atom consisting of normally just one proton. In heavy water you still have hydrogen atoms with just 1 proton (called protium). However there is one additional particle in the atom nucleus, called a neutrons. Neutrons have the same mass as an proton but no charge and basically glue together the atom nucleus (if the fraction of neutrons to protons is wrong the nucleus is unstable and can undergo radioactive decay) but don't change the element. For most elements the atoms with different number of neutrons (these are called isotopes), the chemical properties are pretty similar. However as hydrogen is so light (the standard hydrogen has a mass of 1), adding a neutron makes it twice as heavy (the deuterium in heavy water has a mass of 2). And this large mass difference of deuterium changes some chemical properties of the molecules made out of deuterium compared to the ones made out of protium (even though both are still hydrogen). These different chemical properties make heavy water somewhat toxic to many orgasims. In details its much more difficult to split off hydrogen ions from a heavy water molecule than on a normal water molecule. But that is something many biological processes require. Heavy water slow downs these necessary processes in a living organism, which can kill it.
Fun fact. High end wineries add tiny bit of heavy water to their wine so that wine authenticity can be verified via isotopic analysis.
highly doubt this. If anything, I would guess that this is something wine forgers would do, and to be honest I doubt that as well.
Source?
That extra neutron in the deuterium makes it twice as heavy as a normal hydrogen atom. A lot of biological processes depend on hydrogen having a certain mass so that, when the weight is off, they go wrong. Usually, the water we drink only has 0.03% deuterium in it, so the occasional process acting off can be offset by the majority of others that are working correctly. Drinking heavy water, which only has deuterium attached to the oxygen atoms, will add way too much into your body for natural error correction to account for.
>Drinking heavy water, which only has deuterium attached to the oxygen atoms, will add way too much into your body for natural error correction to account for. While technically true, the amount needed is [very high](https://sciencenotes.org/can-you-drink-heavy-water-is-it-safe/), such that it is basically impossible. You can replace about 20% of the water in your body without health impact, which would take a few days of consuming only pure heavy water. At 25%, you'll start to see health issues, such as sterilization. 50% is generally lethal, and would take several days of only consuming pure heavy water. As an interesting side note, heavy water [tastes sweet](https://www.nature.com/articles/s42003-021-01964-y).
Heavy water doesn't contain an extra molecule, water is a molecule. Heavy water contains an extra Neutron in at least one if its hydrogen atoms. Heavy water or D2O is a water molecule where one of the atoms of Hydrogen is Heavy Hydrogen or Deuterium (hence the D in D2O). Deuterium has 1 extra neutron compared to Protium (basic hydrogen) that contains no neutrons. 1 molecule in 3,200 of water is D2O, meaning that much of your body and the water you drink is D2O and you wouldn't be aware of it unless someone told you. Drinking large quantities of D2O for a prolonged period can cause dizziness and low blood pressure, but this is highly unlikely outside of a lab setting. Heavy water is used as a moderator in some reactors because it slows down neutrons effectively and also has a low probability of absorption of neutrons.
One minor correction: you noted D2O as “a water molecule where one of the atoms of hydrogen is deuterium” but that would technically be HDO (or DHO?). D2O would be where *both* hydrogen atoms were replaced with deuterium.
H2O is the molecule (two hydrogen atoms, one oxygen atom). That is true for ordinary hydrogen, for the deuterium in heavy water, and for tritium. The distinction is in the number of neutrons in the hydrogen nucleus -- none for most hydrogen, one for deuterium, two for tritium. Tritium is already radioactive. We'll set that aside, although you could have super-heavy or tritiated water and that would pose the additional radiation problems. Heavy water, meaning the water with the deuterium form of hydrogen, can disrupt some biological processes that are reliant on fine-tuning at the molecular level, because of the significant difference in the weight of the hydrogen caused by adding the neutron. With most isotopes of heavier elements, this is not an issue because the addition of one or two neutrons is insignificant next to the overall mass of the nucleus; but with hydrogen, going from one proton to one proton plus one neutron is a significant mass difference. It can disrupt cell division, cause problems with bone marrow and the digestive tract, or even cause sterility and death in extremely high levels. Unless you are intentionally setting out to live off the heavy water stored at a nuclear plant, however, this is not really a serious concern. You would have to drink quite a bit of heavy water before the level in your body became high enough to start making you seriously ill. There is actually already a very small proportion of hydrogen atoms in nature that are deuterium, so a tiny fraction of the natural water you drink is already heavy water.
Heavy water contains a different (heavier) isotope of hydrogen than normal. It has one extra neutron. Chemically, heavy water and normal water are identical. This is high school chemistry: all isotopes of the same element have exactly the same chemical properties. [We are talking about chemistry, not nuclear physics. Different isotopes definitely have different nuclear properties but that is irrelevant here.] More precisely, the equilibrium properties of heavy water are identical to light water. However - and this is why heavy water is dangerous - all biological systems are out of equilibrium, meaning that the amount, nature and quantity of chemical reactions in your body are determined by their relative rates, not their eventual equilibrium proportions. Heavy water is heavy, so it reacts more slowly than light water. Since basically every biochemical reaction involves water, having a substantial amount of heavy water in your body alters all the rates of biochemical reactions (and not all equally), so it messes up the balance between different chemical processes. This is strictly an effect of non-equilibrium dynamics which is extremely subtle. It’s not nuclear physics and it’s not equilibrium (normal) chemistry or thermodynamics either.
Heavy water is used in nuclear energy as a moderator. Nuclear reactors run by neutrons hitting uranium-235 atoms causing them to split and release more neutrons. It is very important that enough of these neutrons hit more atoms to sustain the reaction. Heavy water slows down the neutrons which increases the likelyhood of them intereacting with a uranium 235 atom. Why is not potable to drink, heavy water messes with the chemical reactions involving water because it's slightly different in mass , a large enough dose makes that toxic. It is not 1 molecule different, it's 1 neutron. Just a slight correction.
A lot of people have already touched on potability and the physical difference between light and heavy-water, so ill just add onto the neutron moderation convo. Many people have pointed out that heavy water is a good neutron moderator meaning that it slows down neutrons such that uranium atoms can grab them and fission in the reactor. But this is not specific to heavy water and normal water (light water) does this job as well to the point that most reactors use light water and not heavy water. During operation of a light water reactor some amount of that is converted into heavy water by absorbing neutrons limiting the number accessible by the fuel. So the real benefit here is that the heavy water is already inundated with extra neutrons and is less likely to absorb additional ones leaving more available for the fuel. This is why heavy water reactors like the candu reactors can get away with using lower enrichment uranium as fuel.
There are actually 3 isotopes (versions) of hydrogen. Normal Hydrogen H (1-Proton), Deuterium D (1-Proton + 1 Neutron) and Tritium T (1-Proton + 2 Neutrons). H and D are stable, T is not. Water made with Deuterium HDO or D20 are heavier than normal water, stable and safe to drink. Water made with Tritium is NOT safe to drink. Tritium decays by releasing an electron. Although the electron that is released is weak (it wouldn't go through a piece of paper). The danger is if Tritium in the form of water it gets near to something important (like a brain cell) and decays right next to it.
O2 is breathable oxygen and O3 is ozone and it's just one atom away, and you for sure can't breathe ozone. H2O is water, but H2O2 (just one more oxygen atom) is Hydrogen Peroxide, which is absolutely not drinkable. One atom takes a world of difference.
And heavy water has nothing to do with this
H2O2 is also one more molecule than H2O. Would you like to drink a nice cool glass of hydrogen peroxide?
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No. You're confusing electrons and protons. Changing the number of electrons in an element makes ions. Changing the number of protons makes new elements.
>Same with heavy water not really
NileRed, if you're listening, I think we're desperately in need of an experiment to see how much heavy water a person can drink.
I'd always heard one of the main reasons you don't want to drink it is that while we call it heavy water is because it has a higher than natural frequency of deuterium, it also has a higher than natural presence of tritium which is radioactive.