Drill – 10/25
1. Write the nuclear equation for the alpha decay of Pu-239
2. Write the nuclear equation for the electron capture of Argon-37.
Test on Thursday – 10/28From Chapter 3:
– Atomic number, Average Atomic Mass, Mass #– Protons, neutrons, electrons– Ions & Isotopes– Calculating average atomic mass– Atomic Structure History (know famous
scientists/experiments/atomic models)– Mole, Molar mass, & Avogadro’s number– Converting between moles, mass, & particles
From Chapter 21:– Balancing nuclear reactions– Types of radioactive decay (alpha, beta, gamma, positron,
electron capture)– Why radioactive decay occurs– Half-life – Fusion & Fission
• Alpha & beta do not cause internal harm to humans
• Gamma radiation harms living cells. It is used to clean medical equipment and irradiation of bacteria from foods.
• Gamma radiation can break DNA strands and cause mutations (ex. in the gene to suppress tumor production and the gene to repair DNA), causing cancer.
• Gamma radiation can also treat cancer by killing cancer cells. The radiation is directed at cancer cells and kills them first because they are replicating the fastest.
A-bombs• Atomic bombs are an
example of Fission Reactions.
• “Little boy” and “Fat man” were Atomic bombs made from fission reactions with uranium and plutonium respectively.
• A fission chain reaction is started and continues until the bomb destroys itself.
Nuclear Power Plants• Uranium-235 undergoes nuclear fission
and releases thermal (heat) energy. • This turns water to steam which spins
turbines.• The turbines produce electrical energy.
• Nuclear waste is fuel rods with unreacted uranium and radioactive products of fission. Right now this waste is buried in waste management facilities, like Yucca Mountain.
Nuclear Fusion• Low-mass nuclei combine to form a
heavier, more stable nucleus.
Requires high temperatures and/or pressure and often a fission reaction to get the initial particles.
Hydrogen Bombs
• Hydrogen bombs are an example of nuclear fusion.
• Two isotopes of hydrogen, 2H and 3H, fuse together to produce a lot of energy in the process.
• H-bombs release significantly more energy than atomic bombs.
The Sun: Nuclear Fusion
Sun
+ +
Fourhydrogen
nuclei(protons)
Two betaparticles
(electrons)
Oneheliumnucleus
He e2 H4 4
2
0
1-
1
1 + Energy