Question

chemistry semester 1 exam on level 25-26
isotopes are atoms of the same element that differ in the number of _____.
protons
neutrons
electrons
ions

Explanation:

Isotopes are defined as atoms of the same element with the same number of protons (which determines the element's identity) but a different number of neutrons. Protons determine the element, so same - element atoms have the same number of protons. Electrons affect the charge (ions) or bonding, not the isotope definition. Ions are charged particles, not a sub - atomic particle count difference for isotopes. So isotopes differ in neutrons.

Answer:

B. neutrons