Isotopes of an element have
The same number of protons but different numbers of neutrons.
The same number of neutrons and electrons
The same number of protons and neutrons
The same number of protons and electrons
Correct answer is A
Isotopes of an element have the same number of protons (which defines the element) but may have different numbers of neutrons. Since atoms are electrically neutral, the number of protons must equal the number of electrons in an atom.