. Identify the wrong statement in the following

(a) Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius.

(b) Amongst isoelectronic species, greater the negative charge on the anion, larger is the ionic radius.

(c) Atomic radius of the elements increases as one moves down the first group of the periodic table.

(d) Atomic radius of the elements decreases as one moves across from left to right in the 2nd period of the periodic table.

Best Answer

Correct Option is: A

A cation i.e. atom that has lost an electron is always smaller than its parent neutral atom, whereas an anion i.e. atom that has gained an electron is always larger. When one or more electrons are removed from a neutral atom, two things happen: first, as fewer electrons are present, repulsions between electrons in the same principal shell decrease, and second, the effective nuclear charge felt by the remaining electrons increases as fewer electrons shield each other from the nucleus. As a result, the size of the electron-occupied space reduces, and the ion shrinks. The ion with the largest positive charge is the smallest when different numbers of electrons can be removed to form ions with varying charges. When one or more electrons are added to a neutral atom, electron–electron repulsions rise and the effective nuclear charge decreases, causing the atom's size to expand.

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