Question

When a light of suitable wavelength/frequency is incident on a metallic surface, electrons

• A. inside the atoms of the metal are ejected.
• B. which come in contact with the light ray are ejected.
• C. in the outermost orbits of the atoms of the metal are ejected.
• D. in the atoms of the gases present in air are ejected.

Answer 1

The correct option is C in the outermost orbits of the atoms of the metal are ejected.

When a light of suitable wavelength/frequency is incident on a metal surface, electron in the outermost orbit of atom of metals get ejected.

Because electrons in the outermost orbit of an atom are called valence electrons and are most loosely bound to an atom. When a light of certain frequency strikes on it , it absorbs energy and because these electrons are loosely bound , they easily leave the atom and repelled out as compared to electrons in the inner orbit which are tightly bound to nucleus.