Grade 12 Alternate E-Day Task (Photons and Electrons)

Complete Activity 9.1 in your workbook page 274 and upload your answers

Which electromagnetic radiation (EMR) was discovered by placing a thermometer next to the red light?

The greater the frequency of the EMR, the smaller its wave.

What metal is placed on the electroscope?

The plate has to be negatively charged.

Match the correct observations. Drag the observation to the correct light source.

The brightness of the visible light will cause the gold leave to drop.

One photon of light releases

Define work function of a metal.

What metal is placed on the electrode?

What was the wavelength of the incident waves when the first observed electrons moved away from the cathode? Write down the value(number) only using ? (unit is nm)

Use the formula

to determine the frequency in Hz of this incident radiation. write down the value only.

If the frequency of incident radiation is

Hz, calculate the energy carried by one photon of this light ?

Explain what is meant by the photoelectric effect.

How does an increasing the intensity of light affect the current in the circuit. Assume the light has a frequency greater than the threshold frequency. (increase, decrease, remains unchanged)

Are electrons ejected from a metal when the the incident radiation is below the threshold frequency? (yes/No)

Which metal is placed on the cathode now?

Why does this metal require a greater frequency of incident radiation to cause electrons to be ejected ?

What maximum wavelength is required to eject electrons from this metal

What does an increase in intensity of incident radiation produce before it strikes the metal?

Light is made up of

What field of physics did this discovery by Albert Einstein open up?