Among the following, find the total number or possible isotopic pairs formed by the given atoms.

$(232,90);(228,88);(228,89);(228,90);(224,88);$

$(216,84);(213,84)$.

Chemical species known as isotopes are those with the same atomic number but differing masses.

The pair is represented as(Atomic weight, atomic mass)

The correct pair of the isotopes are,

$\begin{array}{l}(232,90);(228,90)\\ (228,88);(224,88)\\ (216,84);(213,84)\end{array}$