Which of the following is the best definition of an atom? a) charged particles that make up all living things b) negatively charged particles that flow in electric current c) small particles that make up all matter

C would be correct because atoms can be either negative or positive charged and they can make up living and nonliving things

The answer to your question is C.) Small particles that make up all matter. 

This is the answer because:

B is incorrect. An atom is both positive and negative as it has both protons and electrons. So B is automatically out because it only says negative. 

A is incorrect. Although it is true that atoms are charged particles, they don't just make up living things. They make up all matter. 

So you are left with C which is true that atoms are both small particles and they make up all matter .

Hope this helped!

Mgo2 is the oxidation state of manganese oxide

Its a hope this