X-ray

Key Stage 4

Meaning

X-rays are the second highest frequency and second shortest wavelength electromagnetic waves.

About X-rays

X-rays are transverse waves.

X-rays can travel through a vacuum as well as through gases in the Earth's atmosphere.

The speed of x-rays through a vacuum is 300,000,000m/s.

As a wave x-rays can be:

• Transmitted - X-rays can pass through a medium.
• Absorbed - The energy transferred by x-rays can be taken in by certain materials.
• Reflected - X-rays can bounce off an interface between two media, particularly the surface of a shiny metal.
• Refracted - X-rays can change direction when they cross the interface between two media.

Unique Properties

X-rays can cause electrons in many materials to gain enough energy to leave atoms creating ions which can destroy chemical bonds.

X-rays can penetrate soft tissue such as the skin.

X-rays are refracted by bones.

X-rays cannot pass through heavy metals (metals with a high atomic mass).

Applications

X-rays can be used to create medical images of bones because they can penetrate soft tissue such as the skin and are refracted by bones.

X-rays can be used to create medical images of the intestines when a human ingests Barium Sulphate because X-rays cannot pass through heavy metals (metals with a high atomic mass).

Dangers

X-rays can cause cancer because x-rays can penetrate soft tissue and can ionise and damage DNA molecules in the body cells leading to a mutation.

Beyond the Curriculum

References

AQA

X-ray diffraction, page 257, GCSE Chemistry; Student Book, Collins, AQA

X-rays, pages 122, 124-5, 196-7, 208, 213, 216-17, 282, GCSE Physics; Student Book, Collins, AQA

X-rays, pages 194, 199, GCSE Physics, Hodder, AQA

X-rays, pages 200, 208, 211, GCSE Combined Science Trilogy; Physics, CGP, AQA

X-rays, pages 223, 225, 228, GCSE Combined Science; The Revision Guide, CGP, AQA

X-rays, pages 242, 250, 251, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA

X-rays, pages 261, 266, 268, GCSE Combined Science Trilogy 2, Hodder, AQA

X-rays, pages 80, 81, GCSE Physics; The Revision Guide, CGP, AQA

X-rays, pages 99, 196-199, GCSE Physics; Third Edition, Oxford University Press, AQA

X-rays; uses and applications, page 201, GCSE Physics, Hodder, AQA