Question

Which of the following is/are correct regarding isotopes and isobars?

• A. Isotopes have the same atomic number but different atomic mass.
• B. Isotopes have a different atomic number but the same atomic mass.
• C. Isobars have the same atomic mass but a different atomic numbers
• D. Isobars have same atomic numbers but different atomic mass

Answer 1

Answer: (A), (C)

The correct options are
A

Isotopes have the same atomic number but different atomic mass.

C

Isobars have the same atomic mass but a different atomic numbers

Isotopes have the same atomic number but different atomic mass.

$C_6^{12}{C}_6^{13}{C}_6^{14}$ are all isotopes as they have the same number of protons, i.e. 6, but different atomic mass.

Isobars have the same atomic mass but a different atomic number.

$C{l}_{17}^{40}C{a}_{20}^{40}$ are isobars as they have same atomic mass, i.e. 40, but a different atomic number.