8-4+Vocab

**Atom**-The smallest particle of and element that retains all th properties of that element. **Gamma Ray**- High-energy radiation that has no electrical charge and mass,is not deflected by electric or magnetic fields. **Nucleus**- The extremely small ,positively charged, dense center of an atom that contains positively charge protons. **Radiation** - The rays and particles, - alpha and beta particles and gamma rays - that are emitted by radioactive materials. **Radioactive Decay**- The spontaneous process in which unstable nuclei lose energy by emitting radiation **Radioactivity** - The process in which some substances spontaneously emit radiation
 * Alpha Particlep**- A particale with two protons and two neutrons ,with a charge is equivalent to a helium-4 nucleus can be represent as and is emitted during radioactive decay.
 * Alpha Radiation**- radiation that is made up of alpha particles.
 * Atomic Mass unit-** One- tweflth the mass of a carbon -12 atom
 * Atomic number**- The numer of protons in a atom.
 * Beta Particle**-A high speed electron with a 1-charge that i emitted during radioactive decay.
 * Beta radiation**-Radiation that is made up of beta particles,Deflected towards a postively charge plate when radiation from radioactive source is directed between two electrically charged plates.
 * Cathode Ray- ** A ray of radiation that orginiates from the cathode ray tube.
 * Dalton's Atomic Theory- ** A theory proposed by john dalton in 1808,marked the beginning of te development of modern atomic theroy.
 * Electron- A ** negatively charged, fast moving particle with an extremely small mass that is found in all forms of matter and moves.
 * Isotope- ** Atoms of the same element with the same number of protons but different numb of nuetrons
 * Mass number- ** A measure of the amount of matter.
 * Neutron- ** An neutral subatombic particle in an atom's nucleus that has a mass nearly equal to that of proton.
 * Nuclear Equation- ** A type of equation that shows the atomic number of the particles involved.
 * Nuclear ** **Reaction-** A reaction that invovles a change ithe nucleus of an atom.
 * Proton - ** A subatomic particle in an atom's nucleus that has a postive charge of 1+.