Question

Atoms that vary in the number of neutrons found in their nuclei are called ________.

a) Isotopes
b) Ions
c) Elements
d) Molecules

Answer 1

Isotopes are atoms that have the same atomic number but different numbers of neutrons, leading to different mass numbers.

Step-by-step explanation:

Atoms that vary in the number of neutrons found in their nuclei are called isotopes. An isotope of a given element has the same atomic number, which determines the number of protons, but a different mass number. The mass number is the sum of protons and neutrons in the nucleus. Isotopes exhibit the same chemical behavior due to having the same number of protons and electrons, but they differ in their atomic mass. For example, carbon has isotopes with six, seven, or eight neutrons, resulting in mass numbers of 12, 13, and 14, respectively, while the atomic number remains constant at six.