Chapter 9 Flashcards
Radioactivity
An unstable nucleus emits one or more particles or energy in the form of electromagnetic radiation
Nuclear decay
Anytime an unstable nucleus emits alpha or beta particles and then the number of protons or neutrons changes.
Nuclear radiation
It is the particles that are released from the nucleus during radioactive decay.
Alpha particle
A positive atom that is released in the disintegration of radioactive elements and includes 2 protons and 2 neutrons.
Beta particle
A charged electron emitted during certain types of radioactive decay.
Neutron emission
Matter that is emitted from an unstable nucleus.
Gamma ray
High energy proton emitted by a nucleus during fission and radioactive decay.
Half-life
The time needed to disintegrate half of a radioactive sample by radioactive decay or by natural processes.
Fission
A process in which a nucleus splits into fragments and releases neutrons and energy.
Nuclear chain reaction
An ongoing series of nuclear fission reactions
Critical mass
The minimum mass of a fissionable isotope that gives the number of neutrons needed to continue a chain reaction.
Fusion
A process in which nuclei combine at high temperature and produces heavier nuclei and releases energy.
Strong nuclear force
The force that holds nuclei together.
Background radiation
The radiation that naturally occurs from comic rays and radioactive isotopes in the soil and air.
Rem
The quantity of ionizing radiation that does damage to human tissue.
