What is Radioactivity?What is Radioactivity?

18.118.1

Nuclear RadiationNuclear RadiationRadioactive Materials-unstable nucleiRadioactive Materials-unstable nuclei Strong Force b/t p and n Strong Force b/t p and n bigger the atom, weaker the force (83 and up)bigger the atom, weaker the force (83 and up)Radiation=Release particles/energyRadiation=Release particles/energyNuclear decay=transform into an isotope or Nuclear decay=transform into an isotope or

new elementnew elementRatio of neutrons to protons= nuclei stability Ratio of neutrons to protons= nuclei stability Radon-natural radiation from EarthRadon-natural radiation from Earth

http://www.no-nukes.org/prairieisland/lesson.htmlhttp://www.no-nukes.org/prairieisland/lesson.html

Isotopes areIsotopes areWritten differentWritten different

TYPE OF RADIATIONTYPE OF RADIATION

1.) Alpha- protons & neutrons +2 He1.) Alpha- protons & neutrons +2 HeUranium-238 Uranium-238 Positive-Large-Can’t pass through a Piece of PaperPositive-Large-Can’t pass through a Piece of Paper

2.) Beta-electrons Neutron Decay -1 e2.) Beta-electrons Neutron Decay -1 eEmits negative-Can’t pass through Aluminum/woodEmits negative-Can’t pass through Aluminum/wood

3.) Gamma- high energy light3.) Gamma- high energy lightNo charge-speed of light-penetrate through lead-No charge-speed of light-penetrate through lead-

dangerousdangerous

Nuclear DecayNuclear DecayAlpha Decay-gives up 2 protons and 2 Alpha Decay-gives up 2 protons and 2

neutrons (neutrons (Transmutation)Transmutation)

Mass # & Atomic #’s add up.Mass # & Atomic #’s add up.Beta Decay-Gains a proton and loses a Beta Decay-Gains a proton and loses a

neutron neutron

Radioactive Decay RatesRadioactive Decay Rates Impossible to predict when the nucleus Impossible to predict when the nucleus

decays….decays….Predict Half life of the nucleusPredict Half life of the nucleusDifferent Isotopes have different ½ livesDifferent Isotopes have different ½ livesHalf-life can be nanoseconds to billions of Half-life can be nanoseconds to billions of

years!years!Carbon Dating-find how old something is.Carbon Dating-find how old something is.