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Ultra-violet

Key Stage 4

Meaning

Ultra-violet is the third highest frequency and third shortest wavelength electromagnetic waves.

About Ultra-violet

Ultra-violet is a transverse waves.
Ultra-violet can travel through a vacuum as well as through gases in the Earth's atmosphere.
The speed of ultra-violet through a vacuum is 300,000,000m/s.

As a wave ultra-violets can be:

Unique Properties

Ultra-violet can cause electrons in some materials to gain enough energy to leave atoms creating ions which can destroy chemical bonds.
Ultra-violet does not penetrate through the skin.
Ultra-violet is scattered by the Earth's atmosphere.

Applications

Ultra-violet can cause electrons in the atoms of fluorescent molecules to gain energy. When the electrons lose this energy they emit visible light. This can be used to reveal fluorescent ink to detect forged bank notes
Ultra-violet causes damage to the skin by breaking chemical bonds so in an effort to protect itself the skin produces melanin, a brown pigment. This causes the skin to become tanned. This is used in tanning beds.
Ultra-violet can destroy micro-organisms in water by breaking chemical bonds in those micro-organisms, so can be used to sterilise water.

Dangers

Ultra-violet can cause sunburn and skin cancer by ionising and damaging DNA molecules in the skin cells leading to a mutation.
Ultra-violet can cause cataracts as it damages the transparent protective layer on the eyes called the cornea.

References

AQA

Ultraviolet (UV), pages 200, 207, 211, GCSE Combined Science Trilogy; Physics, CGP, AQA
Ultraviolet (UV), pages 223, 225, 228, GCSE Combined Science; The Revision Guide, CGP, AQA
Ultraviolet (UV), pages 242, 249, 251, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA
Ultraviolet (UV), pages 80, 81, GCSE Physics; The Revision Guide, CGP, AQA
Ultraviolet light, page 121, GCSE Biology; Third Edition, Oxford University Press, AQA
Ultraviolet radiation, pages 191, 197, 213, 218-19, 282, GCSE Physics; Student Book, Collins, AQA
Ultraviolet radiation, pages 261, 266, 267-8, GCSE Combined Science Trilogy 2, Hodder, AQA
Ultraviolet waves, page 196, GCSE Physics; Third Edition, Oxford University Press, AQA
Ultraviolet waves, pages 194, 199, GCSE Physics, Hodder, AQA
Ultraviolet; uses and applications, pages 200-1, GCSE Physics, Hodder, AQA

Edexcel

Ultraviolet (UV) radiation, pages 74, 84, GCSE Physics, Pearson Edexcel
Ultraviolet radiation, page 127, GCSE Physics, CGP, Edexcel
Ultraviolet radiation; dangers, page 136, GCSE Physics, CGP, Edexcel
Ultraviolet radiation; uses, page 134, GCSE Physics, CGP, Edexcel
Ultraviolet, pages 168, 171, GCSE Combined Science; The Revision Guide, CGP, Edexcel
Ultraviolet, pages 43, 47, GCSE Physics; The Revision Guide, CGP, Edexcel

OCR

Ultra-violet (UV) radiation, pages 192, 194, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR
Ultra-violet (UV) radiation, pages 66, 68, 100, Gateway GCSE Physics; The Revision Guide, CGP, OCR
Ultraviolet waves, pages 152-153, 155, Gateway GCSE Physics, Oxford, OCR