6.6.2 Electromagnetic Waves Flashcards
What do electromagnetic waves do?
They transfer energy from a source to an absorber.
What type of wave are electromagnetic waves?
Transverse
What are the similarities between all parts of the electromagnetic spectrum?
They have the same speed; in a vacuum; they are transverse; they can be reflected, refracted and polarised.
What are the differences between the different parts of the electromagnetic spectrum?
They have different frequencies, energies and wavelengths.
What are different regions of the electromagnetic spectrum from lowest to highest frequency?
Radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays
Which region of the electromagnetic spectrum has the highest energy?
Gamma rays
Which region of the electromagnetic spectrum has the longest wavelength?
Radio waves
Name a two uses of radio waves
Communication (television and radio), studying space
Name two uses for microwaves.
Cooking, communication (mobile phones), weather forecasts/satellites
Name two uses for infrared.
Night vision, cooking, remote controls, electrical heaters
Name two uses for visible light
Photography, iris recognition, fibre optic communication
Name two uses for ultraviolet.
Tanning, fluorescent lights, forensics, forgery detection (bank notes/ID cards)
Name two uses for X-rays
Airport scanners, detecting broken bones/medical imaging
Name two uses for gamma rays
Medical treatment/treating cancer, sterilising medical equipment/fresh fruit
Name two uses for gamma rays.
Medical treatment/treating cancer; sterilising medical equipment/fresh fruit
Name a danger radio waves
None known
State a danger of microwaves
Internal heating of tissue
State a danger of infrared.
Skin burns
State the dangers of visible light
Blindness
State the dangers of ultraviolet.
Skin cancer
State the danger of X-rays
Cancer
State the danger of gamma rays
Cancer and cell death.
Which region of the electromagnetic spectrum can our eyes detect?
Visible light only
Give an example of an electromagnetic wave transferring energy.
Infrared radiation given out by a heater causes the room to get hotter.
1000 millisieverts (mSv) is how many sieverts (Sv)
1 Sv
How can the danger presented by radiation be reduced?
Reducing the time of exposure.
Maximising the distance
Putting shielding between you and the source (i.e. sun screen to reduce the risk of skin cancer from UV)
Describe the production and nature of gamma rays.
Changes in the structure of the atomic nucleus result in gamma rays (electromagnetic radiation) being emitted. They can be generated and absorbed over a wide range of frequencies.
What are the three types of ionising radiation?
Ultraviolet, X-rays and gamma rays
What does ionising/ionisation mean?
Ionisation is the creation of positive and negative charged particles from neutral compounds.
Why is ionisation bad?
Ionisation affects complex and sensitive structures in our body like DNA. The affect of ionisation can be to damage and alter DNA leading to cancer or cell death.
