12.1 MC Review

The photoelectric effect demonstrates..

• The wave properties of photons and electrons.

• The particle properties of photons.

• The wave properties of photons.

• The particle properties of photons and electrons.

What is this formula?

• Energy of emitted electrons

• work function

• Energy of photon

• Energy needed to remove electrons

Photoelectric effect refers to the emission of ​ (a)   from a metal surface as a result of the ​ (b)   of electromagnetic wave energy.

• electrons
• absorption
• alpha particles
• emission
• radioactive decay

In photoelectric effect, which factor affects the NUMBER of electrons ejected.

• Potential Energy

• angle of incidence

• frequency

• intensity

Answer explanation

Intensity in EM radiation is the number of photons arriving in certain period of time.

In photoelectric effect, which factor affects the emission of electrons.

• Potential Energy

• angle of incidence

• frequency

• intensity

Answer explanation

If photon has an energy of hƒ, this ƒ must be greater than a particular critical frequency to remove electrons from the metal surface.

In photoelectric effect, which factor affects the maximum KE of ejected electrons from the metal surface.?

• Potential Energy

• angle of incidence

• frequency

• intensity

Answer explanation

If photon has an energy of hƒ,

hƒ = work function - KE

if hƒ is little greater than work function then ...

...KE will be minimum.

In photoelectric effect, which one is related to the work function?

• Threshold Frequency

• angle of incidence

• frequency

• intensity

Answer explanation

Also called critical frequency (ƒ₀).

If photons have a ƒ less than ƒ₀, then no electrons are going to be removed.

• A

• B

• C

• D

Answer explanation

there is NO RELATION between intensity and momentum.

momentum keeps the same.

• A

• B

• C

• D

Answer explanation

I and III are correct.

II : is about evidence for wave properties in particles.

• A

• B

• C

• D

Answer explanation

Option C

using shorter wavelength radiation = larger ƒ

larger ƒ = larger energy on each photon.