1. 10.1 Radioactivity Nuclear Decay Types of Nuclear Radiation
Radioactivity happens when unstable atomic nucleus (called radioactive isotope or radioisotope) emits charged particles/E
Nuclear decay is when atoms of one element change into atoms of another element
Types of Nuclear Radiation
Alpha Decay: U-238 emits + particle (2p+ and 2 neutrons/ looks like He nucleus)
Beta Decay: Th-234 emits – particle (-1/ like e-)
Gamma Decay: more penetrating and ray of energy emitted (no charge)

2. Effects of Nuclear Radiation
Background radiation: radioisotopes occurring naturally in environment
When exceeds background levels nuclear radiation ionizes atoms
ALL damaging to tissues/deeper
How we detect nuclear radiation
Geiger counter: tool to measure amounts
Film: badges: photographic film in paper to monitor radiation exposure

3. 10.2 Rates of Nuclear Decay Half-life
Time required for ½ sample of radioactive isotope to decay (breakdown)
Decay rates are constant for radioisotope

4. Radioactive Dating: Age of an object (fossils) are determined
Compares object’s C-14 levels with C-14 levels in atmosphere

5. 10.3 Artificial Transmutation
In Lab
Nuclear decay is transmutation that happens naturally
Artificially can hit nucleus with high E particles (p+, neutrons, or alpha particles)
Transuranium Elements
Atomic number above 92 (uranium)
All radioactive and not normally found in nature
Synthesized for lab, industrial, consumer use

6. Particle Accelerators
Rutherford (Gold foil guy!)
Used alpha particles
Particle accelerators speed up particles close to speed of light (3.00x108 m/s)
Quark: p+ and neutrons made of even smaller particles, among basic units of matter, 6 types exist

7. 10.4 Fission and Fusion Nuclear Forces Fission
Strong nuclear forces bind p+ and neutrons in nucleus
Short distances, depend on # p+
Nucleus unstable (radioactive) when strong nuclear force can no longer overcome repulsive electric forces of p+
Fission
German chemists: Otto Hahn and Fritz Strassman
Splitting of atomic nucleus into 2
Were originally trying to make more massive elements, but made isotopes that were smaller!

8. Mass-Energy: E=mc2 Chain Reaction Nuclear E from Fission Fusion
Neutron released during initial split trigger additional splitting
Nuclear E from Fission
Nuclear power plants generate 20% E in US
+ don’t make pollution, - make radioactive waste
Chernobyl, Ukraine (’86) or 2 mile island, PA (’79)
Fusion
Nuclei combine to make larger nuclei