Atom consist of electrons , protons and neutrons . If the mass attributed to neutron were halved and that attributed to the electrons were doubled , the atomic mass of ` 6C^(12)` would be approximately :

Options

A. Twice
B. `75 %` less
C. `25 %` less
D. one-half of its

Answer

C

Explanation

( c) `A = P + n` `A = Z + n`
`A = 12` `Z = 6`
`n = 12 - 6` `n = 6`
=` (9)/(12) xx 100 = 75 % = 100 - 75`
=`25 %` less mass.