radioactivity Flashcards
what happens if an atom absorbs radiation
it moves an electron to a higher energy level which releases radiation when it moves back down an energy level
what is the atomic number
that amount of protons in an atom
what is radioactive decay
it is when an atom has an unstable nucleus so gives out radiation to become stable
what is activity of an atom
activity is the rate at which the unstable nuclei decays
what is activity measured in
becquerels (Bq)
what is the count rate
it is the number of decays each second which can be measured using a Geiger tube
what is a beta particle
it is a high speed electron fired from the nucleus at high speeds and comes from when a nucleus splits into a proton and an electron
what is a gamma ray
it is a type of radiation emitted from the nucleus
what stops each type of radiation
alpha - paper
beta - few millimeters of aluminium
several cm of lead
gamma - several
