Question

Which of the following statements concerning protium, deuterium and tritium is not true?

• A. They are isotopes of each other
• B. They have similar electronic configurations
• C. They exist in the nature in the ratio $1:2:3$
• D. Their atomic masses are in the ratio $1:2:3$

Answer 1

Answer: (C)

Protium is the most abundant isotope of hydrogen. The abundances of protium, deuterium and tritium are $99.984\%,0.016\%$ and $10^{-15}\%$ respectively. The ratio of protium to deuterium is $6400:1$.
Thus, statement $C$ is not true. But statements $A,B$ and $C$ are true. Protium, deuterium, and tritium are isotopes of hydrogen with mass numbers 1,2 and 3 . Their electronic configuration is $1s^1$.