Question

atom a and atom b have the same number of protons, but they do not have the same number of neutrons. which statement describes these atoms? atom a and atom b are isotopes of the same element. atom a and atom b are different elements. atom a and atom b have different atomic numbers. atom a and atom b have the same mass number.

Explanation:

1. Recall the definition of isotopes: Atoms of the same element with the same number of protons (same atomic number) but different numbers of neutrons (different mass numbers) are isotopes.
2. Analyze each option:

• Option 1: Since Atom A and Atom B have the same number of protons (so same element) and different neutrons, they are isotopes. This matches the isotope definition.
• Option 2: Same number of protons means same element (atomic number = number of protons), so they can't be different elements. Eliminate.
• Option 3: Atomic number is number of protons; they have same protons, so same atomic number. Eliminate.
• Option 4: Mass number = protons + neutrons. Different neutrons (same protons) mean different mass numbers. Eliminate.

Answer:

Atom A and Atom B are isotopes of the same element.