A particle detector records an ion made from a neutral atom. The nucleus of the atom has not changed. The ion has relative charge +3. Each electron has a relative charge of -1 and a relative mass of 11840\displaystyle \frac{1}{1840}18401.
Which gives how the ion was formed and how its relative mass compares with the neutral atom?
Three electrons were added; the relative mass is higher by 31840\frac{3}{1840}18403.
Three electrons were added; the relative mass is unchanged.
Three electrons were removed; the relative mass is lower by 31840\frac{3}{1840}18403.
Three electrons were removed; the relative mass is unchanged.