Summary Nuclear Radiation can be naturally occurring or man-made Most of radiation we are exposed to is naturally occurring – alpha rays Alpha Radiation – weakest (blocked by paper or foil) Beta Radiation – medium (blocked by wood) Gamma Radiation – strongest (blocked by lead or concrete) Key Nuclear Science Pioneers – Henri Beckerel, Marie and Pierre Curie

Summary How to Write Nuclear Notation Symbols for: Beta ParticlesAlpha Particles PositronsNeutrons Gamma Rays γ Atomic Mass Atomic No. Element symbol 1n01n0

Summary Balancing Nuclear Equations (Law of Conservation of Mass) Watch for coefficients in front of nuclear particles

Summary Half-Life Related Calculations How to calculate number of half-lives (1/2x1/2x…) How to calculate how old something is (no. of half- lives x time per half-life) Calculate amount remaining (A) after a certain number of half-lives A = Ao (where Ao = original amount) 2 n ( where n = no. of half-lives) Calculate percentage remaining 1 x 100% 2 n (where n = no. of half-lives) Calculate half-life (in years, days, minutes, etc.)

Summary –Describe the difference between: –fission (splitting atoms) 3 steps –Initiation –Propagation –Large production of energy –fusion (combining nuclei) –Describe the pros and cons of each –Identify examples –Examples of beneficial and harmful radiation sources Power generation Medical imaging, diagnostics, disease treatments Food safety Other – historical dating, smoke detectors, etc.