I am at the centre of the atom and contain both neutrons and protons. What am I?

and

Complete the sentence:

Atoms have no overall

charge because ...

An atom consists of a positively charged nucleus, surrounded by one or more negatively charged particles called electrons. The positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral.

Nucleus and atoms have no overall charge because each element has the same number of protons and electrons which cancel out each other.