2. Radioactivity & Half-life
The amount of time it takes for a radioactvity sample to decay to half its original mass is called half-life
Practice. A sample of plutonium has a half-life of 20 years and activity level of 4 curies. After how many years will the activity level of this sample be 0.5 curie?

3. Activity Level Time Half-Lives

4. Practice. A sample of radioactive material has a half-life of 30 years and activity level of 10 curies. After how many years will the activity level of this sample be 1.25 curies?

5. Which country uses the most hydroelectric power? Why?

6. Hydrogen Fuel Cells: How is the hydrogen produced that is used for hydrogen fuel cells?
ELECTROLYSIS – using electricity to drive a nonspontaneous reaction (in this case it produces hydrogen gas)

7. Nuclear Reactor

9. Electric Generator
Converts mechanical energy (spinning turbine) into electrical energy