The electromagnetic spectrum

Question 1

What is radiation

Answer 1

It is the emission of energy from a source which can travel to an object which absorbs the radiation. Most objects that absorb radiation become a little warmer as the radiation affects the atoms the object is made of. If radiation passes through an object we say it is being transmitted through an object.

Question 2

Transmission

Answer 2

What happens when a wave travels through a medium or into a new medium

Question 3

Reflection

Answer 3

When light hits a surface and bounces off at the same angle

Question 4

Absorption

Answer 4

The transfer of energy from a wave to matter as the wave passes through it

Question 5

Emission

Answer 5

When radiation is given out

Question 6

Source

Answer 6

An object that produces radiation

Question 7

Ray

Answer 7

A line that shows that path taken by radiation

Question 8

Model

Answer 8

A way of describing and thinking about a scientific idea that helps us to understand it

Question 9

What is the electromagnetic spectrum

Answer 9

It is a family of transverse waves that travel in a vacuum at 300 million m/s

Question 10

Longest Wavelength/Low Frequency - Shortest wavelength/High frequency

Answer 10

Radio waves
Microwaves
Infrared radiation
Visible Light
Ultraviolet (UV)
X-rays
Gamma rays

Question 11

Gamma rays

Answer 11

Emitted from the nuclei of atoms
It is ionising (can change the atoms inside our cells)
Used for medical imaging, cancer treatment and sterilising medical equipment
Can cause cancer

Question 12

X-rays

Answer 12

Emitted when electron in atoms lose energy
It is ionising (can change the atoms inside our cells)
Used for medical imaging for hospitals and airport security
Can cause skin and tissue cancer

Question 13

Ultraviolet (UV)

Answer 13

Emitted when electrons in atoms lose energy
High energy frequencies are ionising
Used to kill bacteria, causes fluorescence, tanning (sunbeds)

Question 14

Visible light

Answer 14

Emitted when electrons in atoms lose energy
Light reflects off objects
Used for seeing and communication
Very bright light can damage eyes

Question 15

Infrared radiation

Answer 15

Emitted from bonds between vibrating atoms
Causes heating
Used for heating, carrying signals in fibre optic cables, remotes
Can cause burns

Question 16

Microwaves

Answer 16

Emitted by electrons oscillating (moving back and forth)
Causes heating at some frequencies
Used for heating, communications (phones), GPS, radar, SKYTV
Can cause heating at higher frequencies

Question 17

Radio waves

Answer 17

Emitted by electrons oscillating (moving back and forth) in electrical circuits
Causes signals to be transmitted back and forth
Used for communications such as TV and Radio

Question 18

How does electromagnetic radiation affect atoms?

Answer 18

Gamma rays. X-rays and ultraviolet can knock electrons off atoms and turn them into ions. Also, x-rays, ultraviolet and visible light can cause electrons in an atom to jump to a higher energy level. This energy was released when the electron jumps back to a lower level. Infrared radiation waves are absorbed by the bonds of molecules. they can also be re-emitted by the bonds of molecules. Microwaves cause molecules to move. Radio waves cause atoms in wires to move, creating an alternating current.