Question

Difference between Expansion and Contraction.

Answer 1

Expansion means increase in volume of a body without increase in mass(generally) and contractor means decrease in volume.

Answer 2

expansion and contraction...
let's take an example of a ball, precisely an exercise ball like the smiley one.
So, when you squeeze it,it contracts and when you release, it expands.
This is also similar to your lungs, you breathe in, your lungs contract and when you breathe out your lungs expand.