Ineed on this question on my chemistry final exam practice sheet !
50 points

There's basically 3 states of matter, gas, liquid and solid. (There's also plasma but that's whole another thing)

Sample 1 should be liquid. This is because liquid takes up spaces of the container. The molecules can slip past each other at ease as they have a weaker bond to each other. However, they couldn't be compressed so the volume couldn't be changed even in different containers, their volume is fixed. 

Sample 2 should be solid. It has a fixed shape and thus it stays in the shape of a sphere. The molecules are fixed to each other, they have a strong bond between them and they cannot move around, therefore, their shape cannot be changed unless you heat them up and change it to another state. 

Sample 3 should be a gas. Not only they take up the whole container, they can also change its volume depending on the size of the container. Each molecule has a lot of space around and they can move freely in the container as they want to. If the container is smaller, the molecules can be compressed together tighter.  We can prove this by filling a syringe with air, cover the tip with your finger, and try to push the plunger. You should be able to push the plunger without air shooting out because the molecules can be compressed.

So there you have it, we can determine the different state of matter depending on their own properties.  

Sample 1: Liquid

Sample 2: Solid

Sample 3: Gas

The number of protons in a nucleus