Answer :
The polarizability of an atom increases as the increases :
principal quantum number of the valence electron shell
Polarizability can be defined as the ease to with which the electron cloud of the atom is distorted. id the principle quantum number of the valence shell electron increase that means when we move down the group in a periodic table than the valence electrons are loosely bonded to the nucleus and the ionization energy decreases and the polarizability will be increases.
Thus the principal quantum number of the valence electron shell increase will lead to the increase in the polarizability of an atom.
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