Question: if you put a sheet of metal in dryice for long enough could you break it with your bare hands

Hannah Brotherton answered on 20 Jun 2013:

Hi ryan80020,
You would think this would happen, because this happens with other objects like fruit or flowers or clothes. But metal is just a bit too strong for dry ice to have such an effect. But, did you know they already use dry ice on metal to fix dents in car doors. This is because metal bends a bit because it becomes so cold so quickly, it is able to bend a bit. If you have a dent in the door and you leave the car out in the sun (or warm weather), the rapid cooling by placing dry ice on the door, will ‘pop’ the dent right out of it 😀

But something strange happens when you put metal and dry ice together…

It makes this high pitched screeching and screaming noise, like fingernails down a chalkboard. This is because the metal is warmer than the dry ice. When the two make contact, the dry ice turns into a gas. The molecules trapped between the metal and the dry ice don’t have much room to move and expand and start to make the metal vibrate quickly, causing a screaming sound.

This is a great website to see what happens when metal and dry ice come into contact. They use a coin as the metal so the screeching noise is not as much as you would get with a larger piece of metal:

http://science.wonderhowto.com/how-to/make-metal-coin-shake-and-shiver-with-dry-ice-388012/