1. Sci. 4-2 The life Cycle of Stars Pages 105-109

2. A. New stars form from the material of old stars that have gone through their life cycles.

3. B. Hertzsprung- Russell or H-R Diagram- a graph showing the relationship between star’s surface temperature and its absolute magnitude. 1) H-R diagram relates the temperature and brightness of stars. It also illustrates the life cycle of stars.

4. http://www.youtube.com/watch?v=HfqcZdNn Q6s

5. C.Main Sequence- a diagonal pattern of stars on the H-R diagram. 1) Small mass stars are found at the right end. 2) As main sequence stars age, they move up and to the right on the H-R diagram to become giants and supergiants.

6. D. Most stars are main sequence stars. Red giants and white dwarfs are later stages in a star’s life cycle.

7. E.Blue stars may explode in a tremendous flash of light called a supernova. 1)Supernova- basically the death of a large star by explosion. 2)Silver, gold, and lead are formed by supernova.

8. F. Neutron Star- a star in which all the particles have become neutrons, the collapsed remains of a supernova.

9. G. Pulsars- spinning neutron stars

10. H. Black Holes- an object with more than three solar masses squeezed into a ball only 10 km across whose gravity is so strong that not even light can escape.