Question

which particles account for nearly all of the mass of the atom?
a protons and electrons
b protons and neutrons
c neutrons only
d protons only

Explanation:

An atom consists of protons, neutrons, and electrons. Protons and neutrons are located in the nucleus. The mass of an electron is extremely small (about \( \frac{1}{1836}\) of the mass of a proton). Protons and neutrons have relatively large masses. So, protons and neutrons account for nearly all of the atom's mass.

Answer:

B. protons and neutrons