Question

Structures of nuclei of three atoms A, B, and C are given below-

A has 90 protons and 146 neutrons
B has 92 protons and 146 neutrons
C has 90 protons and 148 neutrons

Based on the above data, which of these atoms are isotopes and which are isobars?

• A. A and C are isotopes; B and C are isobars
• B. A and B are isotopes; A and C are isobars
• C. B and C are isobars; A and B are isobars
• D. A and C are isotopes; A and B are isobars

Answer 1

The correct option is A A and C are isotopes; B and C are isobars

${}_{90}^{236}A,{}_{92}^{238}B,{}_{90}^{238}C$

A and C are isotopes because they have the same atomic number.
B and C are isobars have the same mass number.

Hence, the correct option is A.