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The Atomic Nucleus and Radioactivity - Coggle Diagram
The Atomic Nucleus and Radioactivity
What is Radioactivity?
The process of nuclear decay
nothing new in the environment
warms earth's interior
natural
Three types of elemental radiation
Alpha rays- emit positively charged helium nuclei
Beta rays- emit negatively charged electrons from the atom
Gamma rays- electromagnetic radiation
Food irradiation kills microbes
half-life= the rate of radioactive decay of an istotope for its mass to be halved
In 4.5 billion years the uranium now will become lead
What instruments to measure radiation?
Scintillation counter
Geiger counter
Environmental radiation
radon, a common environmental hazard
Most radiation from natural background
1/5 of radiation comes from non-natural sources
lethal doses of radiation occur at 500 rems
radioactive tracers used to identify radioactive isotopes
Radiometric dating
A nitrogen atom that captures a neutron results in a helium and carbon atom
A carbon-12 atom will undergo beta decay and become nitrogen
Relative amounts of C-12 and C-14 enable dating of organic materials
What is transmutation of elements?
It is an element undergoing beta or alpha decay that form a different element
Thorium transmutes to protactinium during beta decay
A alpha particle shot at nitrogen results in oxygen and hydrogen
Atomic nucleus
Strong force (attraction force) hold nucleons together, stronger when protons closer together
Electric force (repulsive force) stronger when subatomic particles are further away from each other
A lone neutron is radioactive and transforms into a proton and emits an electron
Mass-Energy Equivalence E=mc^2
Mass per nucleon vs atomic number graph
Nuclear fission discovered by Hahn and Strassmann in 1938
Nuclear fission is a nucleus striked by neutrons
nuclear fission results in a chain reaction in which the products stimulate further reaction events
critical amount- chain reaction creates an exposition
A breeder reactor breeds Pu-239 and U-238 while burning U-235
