Gr12 Photo-electric effect

Question 1

Describe the photoelectric effect

Answer 1

It is the process whereby electrons are ejected from
a metal surface when light of suitable frequency is incident on that surface.

Question 2

Define threshold frequency

Answer 2

It is the minimum frequency of light needed to emit
electrons from a certain metal surface.

Question 3

Define work function

Answer 3

It is the minimum energy that an electron in the metal needs
to be emitted from the metal surface.

Question 4

Explain the difference between atomic absorption spectra and atomic emission spectra.

Answer 4

An atomic absorption spectrum is formed when certain frequencies of electromagnetic radiation that passes through a medium, e.g. a cold gas, is absorbed.
An atomic emission spectrum is formed when certain frequencies of electromagnetic radiation are emitted due to an atom’s electrons making a transition from a high-energy state to a lower energy state.