An element with mass number 181 contains 32 % more neutrons as compared to protons. What is the symbol of…

An element with mass number 181 contains 32% more neutrons as compared to protons. What is the symbol of that element?
  1. Pt
  2. Pd
  3. Au
  4. Hg

Solution

Let a be the number of protons in an element. 
The number of neutrons is

a+0.32a=1.32a 
As the mass number is 181
It is equal to the sum of the number of protons and the number of neutrons.
181=a + 1.32aa=78

Which is equal to atomic number of Pt.

Asked in: AP EAMCET 2019 (21 Apr Shift 2)

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