B
Atoms of the same element with different numbers of protons
C
Atoms of the same element with the same number of protons but different neutrons
D
Atoms of different elements with the same electrons
Correct Answer: Option C — Atoms of the same element with the same number of protons but different neutrons
Explanation:
Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons resulting in different mass numbers but similar chemical properties.