Non-ionising electromagnetic radiations | Starter Quiz | Oak National Academy

Which of the following happens when a wave is transmitted by a medium?

• The wave bounces off the medium.

• The wave passes through the medium.

• The wave’s energy is absorbed by the medium.

Answer explanation

When a medium transmits a wave, the wave passes through the medium. The word ‘transmit’ is also used to describe what happens when information is communicated from one place to another.

The ___ of a wave is the number of wavelengths per second passing a point.

Answer explanation

The frequency of a wave is the number of wavelengths passing a point each second. So if a person could stand in one place and count how many wavelengths passed by in a given time, the frequency would be: number of wavelengths ÷ time.

Which of the following are examples of ionisation?

• A neutral atom gains a proton.

• A neutral atom loses two protons.

• An neutral atom loses an electron.

Answer explanation

Ionisation occurs when a neutral atom gains or loses one or more electrons, and therefore becomes electrically charged.

Which of the following types of electromagnetic radiation has the longest wavelengths?

• X-rays

• radio waves

• light waves

• infrared waves

• microwaves

Answer explanation

The radiation with the longest wavelength also has the lowest frequency.

Which of the following types of electromagnetic radiation can cause ionisation?

• radio waves

• gamma rays

• ultraviolet waves

• microwaves

• infrared waves

Answer explanation

Gamma rays and ultraviolet waves can cause ionisation (and so can X-rays).

Why are some types of electromagnetic radiation more ionising than others?

• At longer wavelengths, there is more energy per ‘packet’ of radiation.

• At higher frequencies, there is more energy per ‘packet’ of radiation.

• At shorter wavelengths, there is less energy per ‘packet’ of radiation.

• At lower frequencies, there is more energy per ‘packet’ of radiation.

Answer explanation

The higher the frequency, the more energy per ‘packet’ of electromagnetic radiation. If the energy of a packet is high enough, it can cause ionisation of a nearby atom.