Chapter 20:
Stars and Galaxies
Practice Test
1.
Which element forms when four hydrogen atoms fuse together in stars?
a.
carbon
b.
helium
c.
sodium
d.
oxygen
Hint
2.
Why is it difficult to determine the exact shape of the Milky Way Galaxy?
a.
because it contains too many stars
b.
because it is too irregular
c.
because scientists are viewing it from the inside
d.
because it is too far away
Hint
3.
What color are the hottest stars?
a.
yellow
b.
bluish-white
c.
orange
d.
red
Hint
4.
Why is the apparent magnitude of Sirius greater than that of Rigel?
a.
Rigel is cooler than Sirius.
b.
Rigel is larger and hotter than Sirius, but it is farther from Earth.
c.
Sirius is farther from Earth.
Hint
5.
How long does it take for the sun to orbit the center of the Milky Way Galaxy?
a.
240 billion years
b.
240 million years
c.
240 000 years
d.
2400 years
Hint
6.
What causes fusion in stars?
a.
radiation
b.
extreme heat and pressure
c.
sunspots
d.
solar flares
Hint
7.
What is the apparent magnitude of a star?
a.
its observed brightness as seen from Earth
b.
its density
c.
its size
d.
its distance from the sun
Hint
8.
Which layer of the sun is a gradual boundary between the sun and space?
a.
corona
b.
convection zone
c.
chromosphere
d.
photosphere
Hint
9.
What beautiful light show is produced in the northern hemisphere when solar flares interact with Earth's magnetic field?
a.
red giant
b.
twinkling stars
c.
sunspot maximum
d.
aurora borealis
Hint
10.
Select, from the following, the three major types of galaxies.
a.
spiral, linear, and elliptical
b.
irregular, spiral, and elliptical
c.
linear, circular, and elliptical
d.
circular, elliptical, and irregular
Hint
11.
What is a spectrum?
a.
a series of colored elements
b.
a row of red, orange, and yellow giants
c.
a gaseous nebula
d.
bands of colors separated by wavelength as light passes through a prism
Hint
12.
How do stars release energy?
a.
bending light
b.
photosynthesis
c.
fusion
d.
fission
Hint
13.
What causes a nebula to contract?
a.
the speed of the nebula
b.
the gravitational attractions of dust
c.
the temperature of the nebula
d.
the apparent magnitude of the nebula
Hint
14.
Which is true of sunspots?
a.
They are cooler than surrounding areas on the sun's surface.
b.
They are the hottest features on the sun's surface.
c.
They are perfectly smooth surfaces.
d.
They are light-years away from one another.
Hint
15.
What is a light-year?
a.
the distance light travels in one year
b.
about 9.5 trillion km
c.
a large unit of measure
d.
all of the above
Hint
