Question

The mass of a photoelectron is
A. \[9.1 \times {10^{ - 27}}kg\]
B. \[9.1 \times {10^{ - 29}}kg\]
C. \[9.1 \times {10^{ - 31}}kg\]
D. \[9.1 \times {10^{ - 34}}kg\]

Answer 1

Hint: Photoelectrons are the emitted electrons from a surface of a metal due to the interaction of visible light. In other words, when a photon interacts with an atom, an electron is emitted and this emitted electron is called a photoelectron. The word ‘Photo’ means light.

Complete step by step solution:
Consider a metal plate in which the number of atoms is present. When we incident light on the metal plate, since light is made up of energy, this light energy consists of photons, and this photon has some energy. When light strikes an atom, the electron in the atom gains some energy and comes out of the metal plate.

This electron is called a photoelectron. Then the excited electron mass will be \[9.1 \times {10^{ - 31}}kg\] and this is nothing but the mass of a photoelectron or simply electron. Therefore, the mass of the photo electron is \[9.1 \times {10^{ - 31}}kg\].

Hence, option C is the correct answer.

Note: Unlike photons, the photoelectrons have mass and charge. The photoelectrons have different energy depending upon the intensity of incident light. Photon is the smallest packet (quanta) of energy and by the particle nature of light, we can say that the light behaves as particles and this is confirmed by the photoelectric effect, but according to the wave nature of light, light behaves as waves and is confirmed by phenomena like reflection, and refraction, etc. The energy contained in the photon is quantized, that is it cannot be divided, it is only available in discrete packets of energy.