Question

How can you tell if an atom is an isotope?

Answer 1

Isotopes are atoms of an element with a different number of neutrons. They have the same number of protons but vary in the number of neutrons. The chemical properties of isotopes are the same, but they may differ in their atomic mass.

Step-by-step explanation:

An isotope is an atom of an element with a different number of neutrons than protons in its nucleus. Isotopes of the same element have the same number of protons but vary in the number of neutrons. For example, carbon-12 has 6 protons and 6 neutrons, while carbon-13 has 6 protons and 7 neutrons. The chemical properties of isotopes are the same, but they may differ in their atomic mass.

Answer 2

Look up at the atom on the periodic table of elements and find out what its atomic mass is. Subtract the number of protons from the atomic mass. This is the number of neutrons that the regular version of the atom has. If the number of neutrons in the given atom is different, than it is an isotope.