Radioactive Decay, Nuclear Reactions

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Alpha Decay

unstable atom

more stable atom

alpha particle

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Alpha Decay

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Alpha Decay

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Alpha Decay

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Alpha Decay

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Alpha Decay

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Alpha Decay

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Beta Decay

A beta particle is a fast moving electron which is emitted from the nucleus of an atom undergoing radioactive decay.

Beta decay occurs when a neutron changes into a proton and an electron.

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Beta Decay

As a result of beta decay, the nucleus has one less neutron, but one extra proton.

The atomic number, Z, increases by 1 and the mass number, A, stays the same.

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Beta Decay

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Beta Decay

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Beta Decay

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Beta Decay

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Beta Decay

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Beta Decay

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Gamma Decay

Gamma rays are not charged particles like a and b particles.

Gamma rays are electromagnetic radiation with high frequency.

When atoms decay by emitting a or b particles to form a new atom, the nuclei of the new atom formed may still have too much energy to be completely stable.

This excess energy is emitted as gamma rays (gamma ray photons have energies of ~ 1 x 10-12 J).