Quantum

Question 1

What is the photoelectric effect?

Answer 1

Emission of electrons from the surface of a metal when electromagnetic radiation above a certain frequency is incident on it

Question 2

Give the equation relating energy of a photon of em radiation to its frequency

Answer 2

E = hf = hc/wavelength

Question 3

Define threshold frequency of a metal

Answer 3

Minimum frequency of photons needed for photoelectric emission of electrons from the metal

Question 4

Give the photoelectric effect equation

Answer 4

hf = work function + max kinetic energy

Question 5

What is excitation of an atom?

Answer 5

An electron moves up one or more of the energy levels in an atom

Question 6

When an electron moves down one or more energy levels in an atom, what does it emit?

Answer 6

Energy in the form of a photon

Question 7

What do each of the coloured lines in a line emission spectrum correspond with?

Answer 7

A particular wavelength of light emitted by the source

Question 8

When does ionisation occur?

Answer 8

When an electron gains enough energy to leave the atom

Question 9

Define the electron volt

Answer 9

Energy gained by an electron accelerated through a potential difference of 1v

1eV = 1.6x10^-19V

Question 10

Identify the phenomena that can only be explained by the wave model of light

Answer 10

Diffraction and interference

Question 11

What did de broglie propose about the nature of particles?

Answer 11

All matter particles have wave properties