em spectrum and ionising

Radio waves properties

Longest wavelength, lowest frequency and energy, transverse waves that travel at the speed of light in a vacuum.

Radio waves uses

Radio and TV broadcasting, wireless communication.

Radio waves hazards

Very low risk, but high intensity radio waves can cause heating of body tissue.

Microwaves properties

Shorter wavelength than radio waves, transverse waves, travel at the speed of light in a vacuum, can penetrate food.

Microwaves uses

Cooking food, mobile phones, satellite communication.

Microwaves hazards

Internal heating of body tissues which can damage organs.

Infrared properties

Emitted by warm objects, felt as heat, transverse waves that travel at the speed of light in a vacuum.

Infrared uses

Heaters, thermal imaging, remote controls.

Infrared hazards

Skin burns and eye damage from intense infrared radiation.

Visible light properties

Part of the EM spectrum humans can see, transverse waves, different colours have different wavelengths, travel at the speed of light in a vacuum.

Visible light uses

Vision, photography, fibre optic communication.

Visible light hazards

Eye damage from very bright light such as lasers or the Sun.

Ultraviolet properties

Higher frequency and energy than visible light, transverse waves, can cause chemical changes.

Ultraviolet uses

Sterilising equipment, security markings, sun tanning.

Ultraviolet hazards

Sunburn, skin ageing, skin cancer, eye damage.

X-rays properties

Very high frequency and energy, short wavelength, transverse waves, pass through soft tissue but absorbed by bone.

X-rays uses

Medical imaging, airport security scanners.

X-rays hazards

Ionising radiation that damages DNA and increases cancer risk.

Gamma rays properties

Highest frequency and energy, shortest wavelength, transverse waves, very penetrating.

Gamma rays uses

Treating cancer (radiotherapy), sterilising food and medical equipment.

Gamma rays hazards

Severe cell damage, radiation sickness, very high cancer risk.

Ionising radiation definition

Radiation with enough energy to remove electrons from atoms, causing damage to cells and DNA.

Non-ionising radiation definition

Radiation that does not have enough energy to remove electrons from atoms and mainly causes heating.

Ionising EM waves

Ultraviolet, X-rays, Gamma rays.

Non-ionising EM waves

Radio waves, Microwaves, Infrared, Visible light.

Why ionising radiation is dangerous

It damages DNA and cells which can lead to mutations and cancer.

Why non-ionising radiation is less dangerous

It does not damage DNA and mainly causes heating effects.

Most dangerous EM waves

Gamma rays because they have the highest frequency and energy.

Relationship between frequency and danger

Higher frequency means higher energy and greater danger.

How ionising radiation causes cancer

Damage to DNA causes uncontrolled cell division.

Why X-rays are limited in hospitals

To reduce the risk of DNA damage and cancer.

Safety when using ionising radiation

Exposure time is kept as short as possible and shielding is used.

Key exam fact about ionising radiation

Ultraviolet, X-rays and Gamma rays are ionising and can damage DNA.