Which subatomic particles are located in the nucleus of an He-4 atom?
(1) electrons and neutrons
(2) electrons and protons
(3) neutrons and protons
(4) neutrons, protons, and electrons
The answer is (3) neutrons and protons. The nucleus of an atom is composed of neutrons and protons. There is only one atom nucleus composed of only protons, Hydrogen. And the electrons are moving in high speed around the nucleus.
