Below are three isotopes of the element carbon. How are the three isotopes different?

Question

a. They have different numbers of electrons.

b. They have different atomic numbers.

c. They have different numbers of protons.

d. They have different numbers of neutrons.

choose the correct answers

Answer 1

The correct answer is:

d. They have different numbers of neutrons.

Isotopes of an element have the same number of protons (and the same atomic number) but differ in the number of neutrons they contain, which gives them different mass numbers. The number of electrons is the same for all isotopes of an element in its neutral state.