Question

STATEMENT - 1: ${}^{20}Ne$ and ${}^{22}Ne$ are isotopes.
STATEMENT - 2: The isotopes of noble gases don't exist because they are inert.

• A. Statement 1 is true but Statement 2 is false
• B. Statement 1 is false but Statement 2 is true
• C. Both Statements are true
• D. Both Statements are false

Answer 1

The correct option is A

Statement 1 is true but Statement 2 is false

Neon ${(}_{10}Ne)$ possesses three stable isotopes, ${}^{20}Ne{,}^{21}Ne$, and ${}^{22}Ne$. Neon exists as three different isotopes, therefore, the assertion is true but the reason is false. Moreover, as it has three isotopes with different abundancies then its average atomic mass is 20.2u but its mass number (number of neutrons + number of protons) is 20.