Ch 18 Flashcards
Atomic number
Equal to number of protons
Isotopes
Atoms of an element which have same number of protons but different number of neutrons in their nuclei
Natural radioactivity
The spontaneous emission of radiation by unstable nuclei
Background radiation
Radiation’s present in atmosphere due to different radioactive substances
Cosmic radiation
The earth and all living things on it also receive radiation from outer space consists of protons electrons and alpha particles and larger nuclei
Secondary radiation
The cosmic radiation interacts with atoms in atmosphere to create a shower to secondary radiation
Nuclear transmutation
The spontaneous process in which a parent unstable nuclide changes into a more stable daughter nuclide with the emission of radiations
Ionization
The phenomenon of which radiation split matter into positive and negative ions
Penetrating power
The strength of radiation to penetrate material is called penetrating power
Half life
The time during which half of the unstable radioactive nuclei disintegrate is called half life of the sample of radioactive element
Stable nuclei
Nuclei which do not emit radiation’s naturally
Nuclear fission
Takes place when a heavy nucleus such as u-235 splits or fission into smaller nuclei by absorbing a slow moving low energy neutron
Nuclear fusion
When two light nuclei combine to form a heavier nucleus
Radioisotope
Artificially produced radioactive elements are called radioactive isotope
