| A | B |
|---|
| alpha particle | Particle containing two protons and two neutrons |
| anode | Electrode with a positive charge |
| atomic number | Number of protons in the nucleus of an atom of a given element |
| beta particle | High-energy electron that comes from the nucleus |
| cathode | Electrode that has a negative change |
| electron | Negatively-charged particle that exists in an electron cloud formation around an atom's nucleus |
| electron cloud | Region surrounding the nucleus where electons are most likely to be found |
| element | Substance that cannot be broken down into simpler substances |
| half-life | Time needed for one half of the mass of a sample of a radioactive isotope to decay |
| isitope | atoms of the same element that have different numbers of neutrons |
| mass number | Sum of neutrons and protons in the nucleus of an aton |
| neutron | Electrically-neutral particle that has the same mass as a proton and found in an atom's nucleus |
| proton | Positively-charged particle in the nucleus of an atom |
| radioactive decay | Release of nuclear particles and energy from unstable atomic nuclei |
| transmutation | Change of one element into another through radioactive decay |
