Question

of a pencil on the 50 yard line.
where is most of the mass in an atom located?
nucleus
electron clouds
what makes up most of the volume of an atom?
protons
neutrons
electrons
empty space

Explanation:

• Atoms consist of a nucleus (containing protons and neutrons) and electron clouds. Protons and neutrons have much greater mass than electrons. So, most of the mass of an atom is in the nucleus.
• In an atom, electrons are in electron - cloud regions around the nucleus. But the vast majority of the volume of an atom is empty space. Protons and neutrons are in the tiny nucleus, and electrons, although in electron clouds, do not take up most of the volume.

Answer:

• For "Where is most of the mass in an atom located?": Nucleus
• For "What makes up most of the volume of an atom?": Empty space