Question

most of the mass in an atom is made up of which of the following? *
protons and electrons
protons and neutrons
neutrons and electrons
electrons and quarks

Explanation:

An atom consists of a nucleus (containing protons and neutrons) and electrons. Protons and neutrons have significant mass, while electrons have negligible mass. So, most of an atom's mass comes from protons and neutrons.

Answer:

protons and neutrons