The Hertzsprung-Russell Diagram

Answer the questions using the above HR Diagram

1. What factor affects the color of a star?

2. What is luminosity?

3. What factor affects the luminosity of a star?

4. What is the approximate surface temperature of the sun?

5. What is the color of the stars with the highest surface temperature?

6. What type of star has a high temperature but a low luminosity?

7. Most of the stars on the HR Diagram are classified as which type of star?

8. How is it possible for white dwarfs to have a lower luminosity than the sun even though the sun is cooler than white dwarfs?

9. What is the color of the stars with the lowest surface temperature?
10. What type of star has a low temperature but a high luminosity?

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.