Question

32 multiple choice 1 point isotopes of an element differ in the number of: protons neutrons electrons quarks

Explanation:

Isotopes of an element have the same number of protons (which defines the element), but different numbers of neutrons. Electrons are involved in chemical bonding and do not define isotopes. Quarks are sub - atomic particles that make up protons and neutrons but are not what differentiates isotopes.

Answer:

B. Neutrons