Assertion (A): Electronic polarizability increases as atoms becomes larger.

Reason (R): For rare gas, ∈₀(∈_r - 1) E = Na_e, where N is number of atoms/m³ and a_e is electronic polarizability of material.

For magnetic shielding, we need a ferromagnetic material.

Many compounds also exhibit semiconducting properties.

Piezoelectricity means the slight change in dimensions of a specimen when an electric field is applied.

A vacant electronic state moves in the same direction as would a positive charge carrier.