Arguably A, B and C are all correct. Atoms of elements can form compounds such as NaCl(table salt). Molecules form molecular compounds and minerals are just complex molecule compounds.
1. A
2.C
3.A
4.C
5.B
I really hope this isn't cheating and that you can actually do this for yourself and you just want to double check. To study just read the Scientific Method and memorize it
Pollution might be the word you are looking for.
Pollution means the introduction of a substance(s) that is harmful to the environment,
