Proton
A positively charged subatomic particle
Electron
A negatively charged subatomic particle
Neutron
A subatomic particle that has no charge
Nucleus
The center of an atom
Ion
An atom that has an electrical charge
Cation
An ion that has a positive charge
Anion
An ion that has a negative charge
Isotopes
Atoms of an element that have different numbers of neutrons
Atomic Number
The number of protons an element has
Mass Number
The total number of protons and neutrons an isotope has
Atomic Mass
The weighed average mass of an element's naturally occurring isotopes
Radioactive Decay
The process by which an unstable atom becomes stable by emitting particles and/or energy from its nucleus
Half Life
The time it takes for half the number of isotopes in a radioactive sample to decay
Alpha Decay
Occurs when an unstable nucleus emits helium nuclei
Beta Decay
Occurs when an unstable nucleus emits electrons
Gamma Decay
Occurs when an unstable nucleus emits high energy radiation
Nuclear Radiation
The particles and energy given off when element undergoes radioactive decay
Nuclear Fission
Occurs when the nucleus of a heavy element splits creating two lighter elements and releasing energy
Nuclear Fusion
Occurs when the nuclei of two light elements join together creating one heavier element and releasing energy
Transmutation
The conversion of one atom of one element to an atom of another element