Firstly these questions are quite simple. You should try to solve your homework by yourself.
Secondly, I think I'm gonna help you.
1.Atom
2.Element
3.Pure substances
4.Mixture
5.Solutions are homogenous mixtures with particle sizes of less than 1nm
Colloids are heterogenous mixtures with particle size of 1 to 1000 nm
Suspensions are heterogenous mixtures with particle sizes above 1 micrometre
