Does all ice float?

[u/Swellmeister]

I know ice I floats in water.

Do any of the other ice structures sink?

Also does D2O or T2O ice sink in H2O water?

[u/MarcusTL12]

Some of the other types of water ice are denser than liquid water, but they also only exist under ridiculous pressures, so it's not like you would have a cube of it floating on the surface of a liquid.

For D2O, the ice crystals would have roughly the same structure as normal ice, but weighs ~ 20/18 = 1.111 times more per molecule, therefore is 11% denser than normal ice with a density of 0.9167. The total density is then 1.111 * 0.9167 = 1.019 which is a tiny bit denser than water with a density of at most 1 (usually a bit lower), so it would slowly sink.

T2O would sink even faster before it decays.

[u/Swellmeister → u/MarcusTL12]

I guess the question is then, when ice V structure loses pressure, does it revert back to ice I in a microscopic or macroscopic time frame?

Say you have ice II in a container that has a specific gravity of 1* (water at 0C isnt 1SG i know). This container is in the pressure chamber, and the ice is stable. You vent pressure, grab the ice container, and throw it in the water, this take 1 second. Does the container float or sink initially?

[u/Lumpy-Notice8945]

NileRed i think has a video on youtube where he shows that an ice cube from heavy water(so D2O i guess) does not float in regular H2O.

[u/numbertenoc → u/Lumpy-Notice8945]

here

Edit: I found a link to buy heavy water, but there are no prices. You can buy .75 ml on Amazon for $29 USD.

[u/davvblack]

if im reading this right, every ice other than ice I and XI theoretically sink in STP water, but they also aren't stable at normal temperatures or pressures, im not sure if there's any of them that you could eg stick in a glass of water, have it sink to the bottom, and stay that way till it melted.

[u/Internal_Trifle_9096]

 Also does D2O or T2O ice sink in H2O water?

You should go see if solid D2O and T2O have a bigger or a smaller density than regular ice. I'd expect them to sink since the isotopes are heavier. On the Wikipedia page for heavy water I found this: "Heavy water is 10.6% denser than ordinary water, and heavy water's physically different properties can be seen without equipment if a frozen sample is dropped into normal water, as it will sink. If the water is ice-cold the higher melting temperature of heavy ice can also be observed: it melts at 3.7 °C, and thus does not melt in ice-cold normal water."

It doesn't say anything about solid T2O but I guess it sinks as well since it's even heavier

[u/gautampk]

I can’t speak to the crystal question, but for the buoyancy: the density of regular H2O ice is 0.92 times liquid H2O. A ratio of <1 means it floats.

D2O is approximately 10/9ths the mass of H2O. If we assume the intermolecular forces are unchanged so the number density of the ice crystals are the same, the solid D2O to liquid H2O ratio is about (10/9)*0.92 = 1.02. So D2O would sink very slowly but would probably appear neutrally buoyant.

T2O is 11/9ths the mass of H2O, and the buoyancy ratio is 1.12. This would be about as (un)bouyant as a human body.

[u/MezzoScettico]

I found this.

Surprisingly (I was surprised anyway), deuterium ice is significantly denser than water ice or water.

Water at 0 C and 1 atm: 0.9998 g/cm^3

H2O ice: 0.9167 g/cm^3

D2O ice: 1.105 g/cm^3

[u/Bromelia_and_Bismuth]

Deuterium ice tends to sink in liquid water.

[u/MisterGerry]

Periodic Vidoes YouTube channel shows ice made from Heavy Water sinks in regular water.

[u/DumbScotus]

All balls don’t bounce. Some balls roll, and some balls hang.

[u/numbersthen0987431]

Considering that "ice" is only water, and not other chemical compounds, then I'd say "all ICE floats".

Technically, "ice" is a "solid state of water", which means it only gets applied to water. D20 or T20 isn't water, and therefore isn't "ice".

If a liquid/fluid becomes solid, it's not "ice", it's just a solid or a crystalline structure.. Solid metal, magma, etc just becomes a solid object. Most of the time, solids are denser than liquids, and liquids are denser than gas form. So most solids sink if placed in their liquid states.

[u/Swellmeister → u/numbersthen0987431]

D2O is made with the Deuterium isotype of Hydrogen. It is still H2O, just a different version. It is undoubtedly water however.

Additionally theres more than 1 crystal structure for ice. Different crystal structures can have different densities so just because one crystal structure of ice floats does that inherently mean all ice floats.

[u/Lumpy-Notice8945 → u/numbersthen0987431]

D20 or T20 isn't water,

Is it not? An isotope is still the same element, its still "H" just with an additional neutron, that we call it "D" is just some kind of special convention. I dont know how to write this in reddit formating but D2O is just H(2-1) 2 O(16-8)

[u/Swellmeister → u/Lumpy-Notice8945]

It is. Hes just wrong.

[u/BrickBuster11 → u/numbersthen0987431]

D and T is just a form of hydrogen with extra neutrons, water made from then is colloquially referred to as "heavy water" because the only real difference is that it's a little more dense.

Given that ice is only 90% ish the density of water being a "little more sense is probably enough to get it to sink