gamma decay

gamma rays and radioactive decay

Gamma rays are produced when radioactive elements decay. Radioactive elements are elements with unstable nuclei. To become more stable, the nuclei undergo radioactive decay. In this process, the nuclei give off energy and may also emit charged particles of matter. Types of radioactive decay include alpha, beta, and gamma decay. In alpha and beta decay, both particles and energy are emitted. In gamma decay, only energy, in the form of gamma rays, is emitted. Alpha and beta decay occur when a nucleus has too many protons or an unstable ratio of protons to neutrons. When the nucleus emits a particle, it gains or loses one or two protons, so the atom becomes a different element. Gamma decay, in contrast, occurs when a nucleus is in an excited state and has too much energy to be stable. This often happens after alpha or beta decay has occurred. Because only energy is emitted during gamma decay, the number of protons remains the same. Therefore, an atom does not become a different element during this type of decay. Q: The Figure 1.1 shows how helium-3 (He-3) decays by emitting a gamma particle. How can you tell that the atom is still the same element after gamma decay occurs? A: The nucleus of the atom has two protons (red) before the reaction occurs. After the nucleus emits the gamma particle, it still has two protons, so the atom is still the same element.


what are gamma rays

Gamma rays are electromagnetic waves. Electromagnetic waves are waves of electric and magnetic energy that travel through space at the speed of light. The energy travels in tiny packets of energy, called photons. Photons of gamma energy are called gamma particles. Other electromagnetic waves include microwaves, light rays, and X rays. Gamma rays have the greatest amount of energy of all electromagnetic waves. Click image to the left or use the URL below. URL:

dangers of gamma radiation

Gamma rays are the most dangerous type of radiation. They can travel farther and penetrate materials more deeply than can the charged particles emitted during alpha and beta decay. Gamma rays can be stopped only by several centimeters of lead or several meters of concrete. Its no surprise that they can penetrate and damage cells deep inside the body.

instructional diagrams

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gamma rays

a) are waves of electric and magnetic energy.

b) travel at the speed of light.

c) have more energy than any other electromagnetic waves.

-->  d) all of the above

radioactive nuclei undergo decay because they are unstable.

-->  a. true

b. false

in gamma decay, both particles of matter and energy are emitted.

a. true

-->  b. false

gamma decay results in a nucleus with a different number of protons.

a. true

-->  b. false

diagram questions

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