Gamma, X-Ray & UV Light

Applied Science: BTEC Level 3 National Extended Diploma, topic 1.7.5

Gamma Rays

Gamma rays carry the most energy of all electromagnetic waves.

Gamma rays are used for medical imaging and therapy, astronomy, sterilisation and food preservation.

Gamma rays carry the most energy. We can use gamma rays to destroy bacteria and tumours.

X-rays carry the second most energy of all the waves in the electromagnetic spectrum.

Low-energy X-rays are used for medical and industrial imaging.
High-energy X-rays are used to treat cancer.
X-rays are also used for security purposes to detect weapons in airports (and other places).

Due to the dangerous nature of X-rays, exposure to X-rays should always be kept to a minimum.
People working with X-ray equipment should always shield themselves to prevent exposure to X-rays.
These people will place materials (metals like lead) between themselves and the X-rays.

X-rays penetrate soft materials (like body tissue).
Bones are dense materials that absorb X-rays. We can use X-rays to build a shaded image of bones and body tissue.

Ultraviolet light is between X-rays and visible light in the electromagnetic spectrum.

Ultraviolet light is used in medical and forensic photography, air purification, disinfection and medical therapy.
Ultraviolet light can also be used to detect fake bank notes.

Exposure to too much ultraviolet light can cause skin burns, skin cancer and cataract formations in the eye.

In lamps, UV photons excite (gives energy to) atoms. The atoms then release visible light.
In sun tanning, UV excites (gives energy to) skin cells. The skin cells then change colour.

Which one of the following is NOT a use of gamma rays?
Which type of electromagnetic waves are the most penetrating and damaging to living tissues and cells?
Which one of these is a use of low-energy X-rays?
Dentists often take X-ray images of a patient's teeth. The dentist operates the X-ray machine from behind a wall. Why does the dentist take this precaution when it is the patient who receives the dose of X-ray radiation?
Which one of these health issues cannot be caused by exposure to too much UV light?