Chapter 8:Radioactivity Flashcards
Radioactivity
is the spontaneous breaking up of unstable nuclei with the emission of one or more types of radiation
Alpha particles
are groups of two protons and two neutrons stuck together (like helium atom)
What is an example of an alpha particle that emits alpha particles?
Americium-241(in smoke detetors)
Beta Particles
Is formed when a neutron in an unstable nucleus is change into a proton and an electron(which is then ejected from the nucleus):
neutron = proton + electron
How far can beta particle penetrate?
They can penetrate 5 millimetres of aluminium
What is an example of a beta particle that emits beta particles?
Carbon-14(used in carbon-14 dating)
Who discovered radioactivity?
Henri Becquerel
What work did Marie and Piere Curie do?
They discoverd polonium and radium
Gamma Radiation
Is simply high-energy electromagnetic radiation wich have high penetrating ability .They can be used to kill cancerous cells.
Nuclear Reaction
is a process that alters the composition,structure or energy of an atomic nucleus
Radioisotopes
is a radioactive isotopes
Half-life
of an element is the time taken for half of the nuclei in any sample to decay.
Radiocarbon Dating
is a technique used to determine the age of an object containing carbon.It is based on the ratio of carbon-14 to carbon-12 in the object.
Medical Use of Isotopes
Gamma rays use to kill cancer cells
Archaeological Use of Isotopes
Carbon-14 is used to estimate the ages of bones and trees.
