If a dispositve ion of an element 'X' consists of 12 protons and 12 neutrons and another dipositve ion of an element 'Y' consists of 18 electrons and twice the number of electrons of dipostive ion X is the number of neutrons of Y. Then the mass number would be in the ratio of

Options

A. ` 1 : 2`
B. ` 3 : 5`
C. `12 : 19`
D. `2 : 3`

Answer

2

Explanation

`X^(+2)=` No . Of protons = 12 (Z)
Neutrons = 12
No . Of electrons = 10
A= 12 + 12 =24
`Y^(+2)` = 18 electrons.
Y = 20 electrons or 20 protons (Z)
A = 20 + 20 = 40
`A_(X):A_(Y)`
`24 : 40`
`3 : 5`