Multiple choice

Which of the following particles contribute to the mass of an atom?

  1. Electrons and neutrons

  2. Neutrons

  3. Protons and neutrons

  4. Protons

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Protons and neutrons are located in the nucleus and account for almost all of the mass of an atom. Electrons are much lighter and contribute very little to the total mass.