# gamma rays

## dangers and uses of gamma rays

The extremely high energy of gamma rays allows them to penetrate just about anything. They can even pass through bones and teeth. This makes gamma rays very dangerous. They can destroy living cells, produce gene mutations, and cause cancer. Ironically, the deadly effects of gamma rays can be used to treat cancer. In this type of treatment, a medical device sends out focused gamma rays that target cancerous cells. The gamma rays kill the cells and destroy the cancer.

## sources of gamma rays

Gamma rays are given off by radioactive atoms and nuclear explosions. They are also given off by the sun and other stars, as well as by collapsing stars in gamma ray bursts. Fortunately, gamma rays from space are absorbed by Earths atmosphere before they can reach the surface. Q: Predict how gamma rays might affect living things on Earth if they werent absorbed by the atmosphere. A: Gamma rays would destroy most living things on Earth because they have so much energy.

## what are gamma rays

As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves.

## the range of electromagnetic waves

Electromagnetic waves transfer energy across space as well as through matter. They vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of electromagnetic waves, shown in the Figure 1.1, is called the electromagnetic spectrum.

## instructional diagrams

No diagram descriptions associated with this lesson

## questions

higher-energy electromagnetic waves have lower frequencies.

``````a. true

-->  b. false
``````

gamma rays have wavelengths shorter than the nucleus of an atom.

``````-->  a. true

b. false
``````

the frequencies of gamma rays are

``````a) higher than 1019 hertz.

b) lower than a billion waves per second.

c) higher than the frequencies of x rays.

-->  d) two of the above
``````

sources of gamma rays include

``````a) the sun.

b) collapsing stars.

-->  d) all of the above
``````

gamma rays from space are absorbed by earths atmosphere.

``````-->  a. true

b. false
``````

gamma rays can pass through

``````a) bones.

b) teeth.

c) skin.

-->  d) all of the above
``````

## diagram questions

No diagram questions associated with this lesson