Question

Number of protons, neutrons and electrons in the element ${}_{89}{X}^{231}$ is

• A. 89, 89, 242
• B. 89, 142, 89
• C. 89, 71, 89
• D. 89, 231, 89

Answer 1

Answer: (B)

Number of p = number of $e^{-}=89$ and neutrons 231 - 89 = 142.