Where is most of an atom's atomic mass?

The nucleus contains the majority of an atom's mass because protons and neutrons are much heavier than electrons, whereas electrons occupy almost all of an atom's volume. The diameter of an atom is on the order of 10−10 m, whereas the diameter of the nucleus is roughly 10−15 m—about 100,000 times smaller.

Explanation:

Nucleus.

Explanation:

d. temperate deciduous forest