Radioactive Decay

- Alpha Decay The emission of an particle from the nucleus of an atom is called alpha decay An alpha particle is just a helium nucleus It consists of 2 protons and 2 neutrons

– Alpha decay The decaying element is transmuted because of a change in charge The mass number of the decaying nucleus is reduced by 4 and the atomic number is reduced by 2

decay example

– Beta decay Beta decay occurs when a neutron is changed to a proton in the nucleus To conserve charge, an electron appears when the neutron changes

– Beta decay Another particle is emitted during beta decay This particle is small, mass less, and charge less It is ejected to conserve momentum it is called the antineutrino

Beta decay example

+ – positron emission Similar to decay Happens when a nucleus has to few neutrons A proton changes to a neutron The atom ejects a positively charged electron or positron to conserve charge

+ – positron emission Similar to beta decay another particle is emitted This particle is small, mass less, and charge less It is ejected to conserve momentum it is called the neutrino

Positron emission example

– Gamma decay Gamma decay occurs when the nucleons redistribute themselves It is a high energy photon the mass number and atomic number remain the same