Question

An element with mass number 81 contains 31.7% more neutrons than protons. Give the atomic number of
the element?​

Answer 1

Answer: Atomic no. Is 35

Explanation: let no. of portions be x.

No. of neutrons = x + 31.7%. Of x = 1.317x

=> 81 = x + 1.317x

=> 81 = 2.317x

=> x = 34.9 or 35

So, Atomic no. = 35

Answer 2

Answer: Atomic no. Is 35

Explanation: let no. of portions be x.

No. of neutrons = x + 31.7%. Of x = 1.317x

=> 81 = x + 1.317x

=> 81 = 2.317x

=> x = 34.9 or 35

So, Atomic no. = 35