Radioactivity Flashcards
Isotopes
Atoms of the same element that differ in the number of neutrons in the nucleus
Stable
Describes a nucleus that does not change spontaneously. The protons and neutrons in the nucleus are held together strongly
Unstable
Describes an atom in which the neutrons and protons in the nucleus are not held together strongly
Radioisotopes
A radioactive form of an isotope
Nuclear radiation
Radiation from the nucleus of an atom, consisting of alpha or beta particles, or gamma rays
Alpha particles
Positively charged nuclei of helium atoms, consisting of two protons and two neutrons
Beta particles
Charged particles (positive or negative) with the same size and mass as electrons
Gamma rays
High-energy electromagnetic radiation during nuclear reactions. They have no mass and travel at the speed of light
Half-life
Time taken for half the radioactive atoms in a sample to decay- that is, change into atoms of a different element
Cosmic radiation
Naturally occurring background radiation from outer space