Today we are going to explore the three states of matter; solid, liquid and gas.
Let's begin by passing around these blue cups...
...look at them closely and see if you can notice any changes as you pass them around.
They are special thermo cups they are blue when they are cold. The heat from your hands gradually makes them change colour into clear cups!
Dry ice is very, very, very cold. It is colder than the North Pole. It is eight times colder than the coldest winter ever known. In fact it is so cold that the temperature of dry ice is around -78VERY COLD! If the dry ice was to touch your skin you would get a cold burn! So you have to be very careful when handling it. It is essential to wear protective gloves.
When I blow on the dry ice...
my warm breath will make the ice melt, not into a liquid but into a gas, carbon dioxide.
By adding boiling water to the dry ice the chemical reaction is even stronger.Look at the vapour, it rises but then goes down. This is because carbon dioxide is heavier than air. (Please scroll down further to view video clips of this reaction.)
I'm caputuring some of the carbon dioxide into this balloon so that we can do a little experiment. If I blow up another balloon it will be filled with a mixture of air/carbon dioxide. If carbon dioxide is heavier than air the green balloon will reach the floor first. Let's test this theory.
Please click on the play button below to see the results of this experiment. The experiment is repeated three times, look carefully at the floor to see if you can spot which balloon reaches the floor first.
Once boiling water is poured onto dry ice the ice turns into a gas which is carbon dioxide. This is called 'sublimate' meaning 'change from a solid to a vapour without first melting'.
Let us see if we can remember this new word 'sublimate' .
Please click on the play button below to view the chemical reaction of boiling water added to dry ice. In the flask with blue colouring Cosmic Chris asks "Can you see the genie"?
We tasted the vapour (cold steam) escaping from the flask, it tasted of sherbert. When all of the dry ice has evaporated the liquid left in the flask tastes of flat fizzy water.
Did you know? You can make dry ice sing! Please click on the play button below to hear the sound that dry ice makes when a warm spoon touches it. Please continue to watch to see what happened when a warm 50p piece was placed into a slot in the ice.
Let's create an awesome smoke illusion, we will make a giant bubbling potion!
Please click on the play button below to see more of our giant bubbling potion!
WOW! Mad Science we have had a fantastic time learning about dry ice!