What do gases have to do with energetic toddlers?
Gases contain molecules floating around and bumping into each other. Take air for example. Air contains mainly molecules of Nitrogen, Oxygen, water vapor, Argon, and Carbon Dioxide. At the molecular lengthscale, these different molecules are bumping into each other constantly like bumping cars at the arcade. But why do molecules in gases keeping bumping around and moving?
Molecules keep bumping around because of temperature. The higher the temperature, more the faster the molecules move and bump into each other.
Molecules at a high temperature are like toddlers in a small room; just after they have eaten loads of candy. They have a lot of energy and keep randomly whizzing around.
When the temperature becomes lower, molecules move slower similar to toddlers who have already run around for half an hour and are now tired.
Absolute Zero
You might ask if molecules get slower with decreasing temperature, when do they completely cease motion; similar to tired toddlers taking a nap? (Apologies for the toddler analogies — that’s the only other thing on my mind these days). It turns out that temperature is a very specific one, called absolute zero. Absolute zero is the coldest temperature ever! It’s -273 C or -459F. Absolute zero sets the temperature scale…
