Question

an atom is mostly made up of neutrons electrons the nucleus empty space

Explanation:

An atom consists of a small, dense nucleus (containing protons and neutrons) and electrons orbiting around it. The nucleus is very small in volume compared to the overall atom, and the space between the nucleus and the electrons (where electrons move) is mostly empty. Neutrons are part of the nucleus, electrons are tiny particles in orbit, and the nucleus is a small part. So an atom is mostly made up of empty space.

Answer:

D. Empty space