Heavy Water - Periodic Table of Videos

We make ice from heavy water - also known as deuterium oxide or D2O - to see if it will sink or float. More links in description below ↓↓↓

[TheBitGuy]

I would think the reason the ice eventually began to float is because once the D20 from the ice started melting, it raised the density of the water around it that it was melting into.

[Chelnaka]

"Where do you get all that stuff, Neil?" *EPIC SHRUG*

[darwinsbitch]

His face when they were telling him the results of the experiment was priceless, he was so excited to hear it. This man loves his job, for some reason that fills me with joy.

[BenJones-kdhs]

I think another factor in the reason why the D2 cubes began to float is because the solution of water they were in gradually increased in concentration of D2 as the cubes melted.

[dercebe]

Great demonstration. One thing that came to my mind, though: It might have been better to color code the H2O in order to avoid the chance of the coloring changing the outcome of the experiment, no one would have asked about ordinary ice, we all know how it behaves. I do not think it really makes much of a difference, but it would have made the results even less questionable.

[wonderpookie]

I watch this video periodically (ha!) throughout the year, just because... still impressed, every single time.
Hats off to all the great individuals involved in its making, thank you!
[secondary school Physics teacher!]

[smoker]

7:08 thats easy man. As D2O ice melts, its mixed with water so water's density will become higher and it will push D2O ice to the top.

[shune]

he had to grow his hair like that because he's a scientist

[showguyer]

Love this channel. So interesting. I know nothing of chemistry but still find it fascinating

[henkmagnetic]

Even after 13 years this video still impresses me with its beauty of educating.

[Kilroyan]

I'd love to be in a position in life where archaic samples of sealed deuterium just casually appear in my possession!

[OwenPrescott]

Neil would probably be a great person to have around during a zombie Apocalypse.

[Rundvelt]

I have a different take on why the D2O is rising.

Can it be that when the ice melts, the D20 changes the density of the water, causing it to become slightly denser.   Given that the cube is close to the same density, this change should slowly move the cube upwards to the top.

Unless I've missed something completely obvious.

[omniwing]

Dear Sir Martyn Poliakoff, You have such a savagely intelligent brain, and an abundance of knowledge that even other academics envy. Yet you still manage to describe concepts in a simple, yet accurate way for the laymen. I love when you pause for a moment and then describe a heavy concept in a succinct way. I salute you, sir.

[kritter]

A nice and very simple experiment. Although I worked with D2O as well during my studies I have never performed this experiment. Yet I have always expected this to happen but have never seen it with my own eyes! The effect of a rising density of the surrounding liquid water should be negligable. The likelier explanation is the one stated: D2O exchanges protons with the surrounding liquid H2O. Sooner or later the whole D2O-ice cube should be substituted by H2O to form a H2O-ice cube... D2O + H2O --> 2 HDO etc....

[richcheema]

"Unless you're trying to make nuclear weapons, and that's a different story" haha

[ShamanBhat]

Maybe that the D2O cube floats up because a layer of D2O is formed at the bottom of the beaker like say a mixture of oil and water... it's just a emulsion. That's why the cube floats
U know what you guys need to do next ?
Put a D2O cube in the beaker take it out after it has melted halfway and then put a new cube of D2O into it just to confirm if it the above mentioned case

[macrocefalo]

I love the videos, but i think what i really like it's that when Brady ask a question, u see the professor thinkiing.

[Faldrian]

I think the Deuterium melted and made the solution of H/D in the beaker heavier, so the force pushing the ice upwards grey stronger due to less difference in weight of the ice-cube compared to the surrounding liquid.

[pottervi]

How cool. You have done countless experiments, ran all the numbers, and are just as excited about a simple experiment as anyone else