Question

Which of the following are isotones?

• A.
• B.
• C.
• D.

Answer 1

Answer: (A), (B), (C)

The correct options are
A

B

C

What do you mean by isotones?

Isotones are atoms of different elements containing same number of neutrons.

Now, Lets calculate number of neutrons.

Number of neutrons = Mass number - Number of protons

$\Rightarrow$ ${}_{15}^{30}Si$ $\to$ 30 - 14 = 16

${}_{15}^{31}Si$ $\to$ 31 - 15 = 16

${}_{16}^{32}Si$ $\to$ 32 - 16 = 16

${}_{17}^{35}Si$ $\to$ 35 - 17 = 18

Therefore,

${}_{15}^{30}Si$ , ${}_{15}^{31}P$ and ${}_{16}^{32}S$ are isotones.