Electromagnetic Spectrum (Yr 9)

EM Spectrum

The collection of all the EM (electromagnetic) waves.

Similarities of EM Waves:

1. They can all travel through a vacuum

2. They all travel at the same speed in a vacuum

3. They are all transverse waves.

Differences of EM Waves:

1. Different wavelengths

2. Different frequencies

3. Different energies

EM Spectrum: (Increasing frequency and decreasing wavelength L to R)

Radio, Microwave, Infrared, Visible light, Ultraviolet, X-Ray, Gamma

Visible Light Spectrum: (Increasing Frequency)

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Uses of each wave:

Radio - Communication, TV and radio signals.

Microwave - Satellite communication, Cooking

Infrared - Cooking, Heaters, Thermal Imaging

Visible - Fibre optic communication, Endoscopes

Ultraviolet - Fluorescent lamps, Tanning

X-Rays - Medical imaging of body

Gamma - Sterilising food/medical equipment

Dangers of each wave:

Radio - No proven dangers

Microwave - Heating of internal tissue

Infrared - Skin burns

Visible - Damage to retina

Ultraviolet - Skin cancer, damage to eyes

X-Rays - Cancer

Gamma - Cancer

Key Wavelengths:

Radio - Metres

Microwaves - Millimetres/Centimetres

Visible Light - 700 nanometres to 400 nanometres (1nm = 10(-9))

X-Rays - 10(-10) metres