Electromagnetic radiation

Question 1

What happens to radiation when it encounters a material in its path?

Answer 1

It can either be reflected, transmitted or absorbed

Question 2

How does a beam of radiation transfer energy?

Answer 2

It transfers energy in packets called photons

Question 3

What affects the amount of energy transferred by each photon?

Answer 3

The higher the frequency that more energy is transferred by each photon

Question 4

What is the order of electromagnetic radiation in terms of frequency?

Answer 4

radio waves, microwaves, infrared, (red) visible light (violet), ultraviolet, X-rays, gamma rays

Question 5

How does the speed of each type of radiation differ?

Answer 5

It does not, all radiation travels at the same speed through space (300000km/s)`

Question 6

How does the intensity of energy change over distance?

Answer 6

As energy travels further it spreads out further too, this means that intensity decreases as distance increases. The intensity is inversely proportional to the square of its distance from the source

Question 7

How is intensity measured?

Answer 7

It is the energy transferred to each square metre of absorbing surface in each second (J / m^2 / s)

Question 8

What can some radiations do to atoms/ molecules and which radiations can?

Answer 8

Some radiation is capable of ionising atoms, the only radiation that can do this is high energy ultraviolet, x-rays and gamma rays. Ionisation is when an atom loses an electron and it can start off a chemical reaction