Answer:
Most of an atom consists of empty space. Its mass is concentrated in its center, which is called the nucleus. The nucleus consists of protons and neutrons.
Explanation:
Answer:Family, Genus, Species.
Explanation:
The prefix "poly-" means "many," and "atomic" refers to atoms, so a polyatomic ion is made of 2+ atoms covalently bonded together. These ions are charged, which is why they can never stand alone.