Caesium in Water (reaction only)

NOTE FROM THE PROFESSOR: The reaction is 2Cs + 2H2O → 2CsOH + H2. However, the H2 can then react with O2 in the air to explode. Also, unlike the other alkali metals, except perhaps Francium, Cs is a liquid just above room temperature so the initial heat of reaction will melt the metal and one has liquid metal reacting with the water.

Periodic Videos films are by video journalist Brady Haran

[allowambeBOWWAMB]

Love this video. Straight to the point, no long intros or any BS :) Good job!!!

[BarneySaysHi]

When he said "Is everybody ready? Neil?" I was almost expecting Neil to say "Does anybody know where the toilets are?"

[fanfan]

My chemistry teacher is obsessed with this video

[Ostsol]

I recall watching a similar experiment in high school. Unfortunately, I'm not sure whether it was a video presentation or if it was during a field trip to the university. Whatever the case, it was just a small tablet-sized chunk of caesium and the bang was still wonderfully impressive.

[Irishkeyblade]

The reactions are only getting more exciting, looking forward to the rest =)

[hitv]

this is probably the greatest reaction out of them all.

[TheReaverOfDarkness]

Elements lower down the column make smaller explosions. The only reason cesium makes much of an explosion at all is because it has such a rapid reaction. It releases much less energy that sodium or potassium in water.

[israellai]

I love alkali metals + water reactions...LOL

[kurtilein]

its more reactive, its just that caesium produces far less hydrogen than potassium by unit of mass. Thats because the individual atoms are much heavier.

[Omni]

I think just the outside reacts so violently it catapulted the rest out, or coated the rest, something like that, it's been a while since I did chemistry.

[vladsinger]

Braniac may have exaggerated a bit with explosives, but /watch?v=uixxJtJPVXk. The ionization energy decreases down the group due to the shielding of the valence electrons by the inner shells. Lower ionization energy --> more readily reacts to produce metal ions in solution. Cesium definitely produces a larger bang.

[zanders]

@TheLonelyImmortal there's no such thing as a chemical that should never be handled. It's more a case of having the correct equipment and skills to do it safely.

[CrimeMinister]

I have heard that Cesium, can become liquid at quite attainable temperatures...Rubidium too. I was wondering if you could somehow set up a reaction with liquid Cesium in water or Rubidium My interest in chemistry actually started with the Alkali/Alkaline Earth metals' reactions with water. Even though it has been 12 years since my start into the world of chemistry, I still would like some closure with this obsession. It would be great if you could do that!

[Damnation]

Sodium and Potassium explosions look bigger because the Hydrogen has time to make nice clouds/bubbles before the metal gets too hot and ignites the Hydrogen.

[Quintinohthree]

It's lower down the column, but the energy produced per gram is less. Explained here: watch?v=jhg0WsINmPc In that video 130 g of caesium is compared with 7 g of lithium. You'll be surprised at the findings.

[FlyingPiper]

The explosion of cesium is faster than potassium, but not exactly bigger.

[mrmoneyoo]

i wish all these hourly videos were all new content =[

[Tacsponge]

but it's heavier, so per gram the reaction will be less

[sincursus]

I read at least 3 different explanations on why this is on the front page. Apparently it's not a well-known answer.

[happyguyeug]

Yes but energy produced per gram is less, i.e you need a lot more caesium than potassium to produce the same amount of energy.