Would you expect `IE_(1)` for two isotopes of the same element to be the same or different? Justify.

Explanation

`rarr` Isotopes means existance of same elements with different mass no.s
`rarr` The isotope with higher mass no. have low I.E value than the normal isotope.
`rarr` This is due to the less nuclear attraction on valency electrons in case of heavier nuclide.
`rarr` But overall, the IE values of the isotopes are nearly same and the difference in IE values is negligible.