Question

An ion having a mass number 52 has 3 units of positive charge . The number of neutrons in the ion exceeds the number of electrons in it by 7. The atomic number of the element is ??

Answer 1

#BAL

Given:

Mass Number = 56

Percentage of neutron = 30.4% more as compared electrons

Let Number of electrons in ion = p

As, it has 3 positive charge

Therefore, number of protons = p + 3

As, number of neutrons are 30.4 % more as compared to number of electrons.

Therefore, number of neutrons= p + 0.304 p =1.304 p

As, we all know that mass number is the sum of number of protons and neutrons.

Therefore,

p + 3 + n = 56

p + 3 + {p + [30.4× p] / 100} = 56

p + 3 + 1.304p = 56

2.304p = 53

p = 53 / 2.304

p = 23

23 is the number of electrons present in that ion.

Therefore, the number of protons = p + 3

                              =23 + 3

= 26

Atomic Number = 26

The element is Iron.

The atomic symbol is Fe3+.