1. Review Quiz No. 16 :60 1.A0 2.B2 3.F5 4.K2 5.G2 Question 1: Stars of which of the following spectral types have the shortest main- sequence life time?

2. Question 2: A star that is “burning” Hydrogen into Helium in an envelope around a central Helium core, is called a :45 1.Red Giant. 2.White Dwarf. 3.Red Dwarf. 4.Brown Dwarf. 5.Shell Star.

3. Question 3: Heavy elements (heavier Carbon and Oxygen) are produced :45 1.in all stars. 2.only in very low mass stars. 3.only in very high mass stars. 4.only in sun-like stars. 5.Depends on the original composition of the stellar material.

4. Question 4: Stars spend most of their active life time :45 1.as protostars. 2.on the main sequence. 3.as red giants. 4.as brown dwarfs. 5.watching TV.