An ion with mass number 56 contains 3 units of positive charge and 30.4% more neutrons than electrons. The ion is ?

Let the number of electrons in ion = X

Number of proton or atomic number of element = X+3

Number of neutrons in ion = X + 30.4% of X = X + 0.304 X

=1.304 X

Atomic mass of an element is sum of the number of neutrons and number of protons of the element.

thus

56 = (X+3) +(1.304 X)

or

X = 23

Hence Atomic number of the element is 23+3 = 26, and the element is Fe,

The ion is Fe³⁺