1. D AILY SCIENCE Write the following elements using short hand notation: 1. Helium 2. Tin 3. Zinc 4. Chlorine 5. Tungsten

2. R ADIOACTIVITY Pg. 33

3. R ADIOACTIVITY Reactions which involve a change in an atom’s nucleus are called nuclear reactions. Radioactivity- the spontaneous emission of radiation (rays and particles) By emitting radiation, atoms of one element can change into atoms of another element. Happens because of unstable nuclei The element undergoing decay is called the parent nuclei New element is called the daughter nuclei

4. R ADIOACTIVE D ECAY Spontaneous process (doesn’t require energy) Nuclei change until there is a stable product. Half-life- the time it takes for ½ of a radioactive isotope to decay into its stable products. Ex. If gallium has a half-life of 68.3 minutes, how much of a 10.0 mg sample is left after 1 half life? After 136.6 minutes? After 3 half-lives?

5. T YPES OF R ADIATION Alpha radiation-  Beta radiation-β Gamma radiation- γ

6. A LPHA R ADIATION Particle deflected toward a negatively charged plate Alpha particles ( ) Equivalent to a helium-4 nucleus Decay equation: Represented by a nuclear equation

7. B ETA D ECAY Deflected toward a positive plate Fast moving electrons ( ) Beta decay results in the creation of a new atom

8. G AMMA R ADIATION High-energy radiation that possess no mass and are denoted by the symbol 0 0 Not deflected when passed through a plate Usually accompany alpha decay