1.The Hertzsprung-Russell Diagram reveals a) the evolutionary properties of stars b) the orbital motion of the planets around the Sun c) the quantum

1.The Hertzsprung-Russell Diagram reveals

a) the evolutionary properties of stars

b) the orbital motion of the planets around the Sun

c) the quantum mechanical properties of the Periodic Table of Elements

d) the chemical composition of dead stars

2.The range of stellar surface temperatures spans about a factor of ___ .

a) 50

b) 2

c) 10

d) 100

3.Do stars have a random distribution of luminosities and surface temperatures?

a) No, they are not random, but, rather, depend on their stage of life.

b) Yes, they are random, according to current measurements.

c) Yes, they are random, but that is an assumption about the properties of stars.

d) No, they are not random. Stars have surface temperatures of about 10,000 Kelvin and a luminosity of about 1026 Watts.

4.Main sequence stars can be

a) cool and very large in size.

b) hot and intrinsically highly luminous.

c) cool and intrinsically highly luminous.

d) hot and intrinsically dim.

5.The vertical axis of the Hertzsprung-Russell Diagram measures

a) the color of a star.

b) the radius of a star.

c) how hot the core of the star is.

d) how much light leaves a star's surface

6.A star with a hotter surface will radiate light at a higher rate than a same sized-surface area of a cooler star.

a)  True

b)  False

7.Betelgeuse is a

a) main sequence star.

b) red supergiant.

c) black hole.

d) white dwarf.

8.Examine Figure 9.1. White dwarfs have a _____ surface temperature, compared to other stars.

a) low

b) high 

9.The axes of the HR Diagram are, for practical reasons, plotted ______.

a) logarithmically

b) linearly

10.The surfaces of the hottest stars reach

a) hundreds of Kelvins.

b) a few millions of Kelvins.

c) tens of thousands of Kelvins.

d) ten million Kelvins.

11.Spectral classes first organized the characteristics of stars according to

a) stellar size.

b) stellar mass.

c) hydrogen absorption features in the spectrum.

d) iron absorption features in the spectrum.

12.Classification of stars was improved in realizing that stars are sequentially different from each other according to ______.

a) location within the galaxy

b) chemical composition

c) surface temperature

13.Measuring the proportions of different _______ allows a calculation of a star's_____ .

a) colors in a star's light; surface temperature

b) elements in a star's composition; radius

c) spectral absorption features; radius

d) elements in a star's composition; surface temperature

14.What temperature need be reached for hydrogen to undergo thermonuclear fusion?

a) one thousand kelvin

b) ten thousand Kelvin

c) one million Kelvin

d) ten million Kelvin

15.Hydrogen fusion produces what element?

a) carbon

b) hydrogen

c) iron

d) helium