Focus On Physical Science: California Grade 8

Unit 4: Earth in Space

Unit Tests

1.
Which equals one astronomical unit? 4.c
A)200 million km
B)75 million km
C)100 million km
D)150 million km
2.
What is Earth's period of rotation? 4.e
A)30 days
B)365 days
C)24 h
D)12 h
3.
The average distance from Pluto to the Sun is about _______. 4.c
A)40 light years
B)40 AU
C)40 million km
D)40,000 AU
4.
The distance from Earth to the nearest galaxy is about _______. 4.c
A)9.5 trillion AU
B)one million AU
C)9.5 trillion yr
D)one million yr
5.
The outward pressure inside a star is due to _______. 4.d
A)nuclear fusion reactions
B)gravitational forces
C)a supernova
D)rapid contraction
6.
Most short-period comets come from the _______. 4.e
A)Kuiper Belt
B)Oort cloud
C)asteroid belt
D)meteoroid belt
7.
A low-mass star, such as the Sun, eventually becomes a _______. 4.b
A)black hole
B)neutron star
C)white dwarf
D)supernova
8.
Which two elements are the main components of stars? 4.d
A)carbon and helium
B)hydrogen and helium
C)carbon and hydrogen
D)helium and oxygen
9.
What does the apparent magnitude of a star depend on? 4.b
A)luminosity and size
B)surface temperature and size
C)color and distance from Earth
D)luminosity and distance from Earth
10.
The elements in a star can be identified by analyzing the star's _______. 4.d
A)temperature
B)continuous spectrum
C)core
D)absorption spectrum
11.
Phases of the Moon occur because the Moon _______. 4.d
A)reflects light emitted by the Sun
B)reflects light emitted by Earth
C)emits light
D)reflects light emitted by all objects in the solar system
12.
Which is a moon of Saturn that has a thick atmosphere. 4.e
A)Titan
B)Io
C)Ganymede
D)Europa
13.
What produces the energy emitted by a star? 4.d
A)chemical reactions in the star's core
B)gravitational compression in the star's core
C)gravitational collapse of the outer layers
D)nuclear fusion reactions in the star's core
14.
Which is not a part of a spiral galaxy? 4.a
A)halo
B)spiral arms
C)supercluster
D)nuclear bulge
15.
Where is the Sun located in the Milky Way Galaxy? 4.b
A)on the edge
B)about halfway from the center to the edge
C)in the nuclear bulge
D)in the halo
16.
Which is not a type of galaxy? 4.a
A)spiral galaxy
B)elliptical galaxy
C)irregular galaxy
D)spherical galaxy
17.
What happens as a protostar continues to contract? 4.d
A)It becomes a white dwarf.
B)It becomes a supernova.
C)Its temperature increases.
D)Its density decreases.
18.
The _______ causes the formation of stars and galaxies. 2.g
A)nuclear force
B)electric force
C)magnetic force
D)gravitational force
19.
Which are rocky objects that are found between the orbits of Mars and Jupiter? 4.e
A)meteorites
B)comets
C)meteoroids
D)asteroids
20.
Which is the best estimate for the number of stars in the Milky Way galaxy? 4.a
A)billions
B)thousands
C)millions
D)trillions
21.
Which planet is made mainly of gases? 4.e
A)Venus
B)Mercury
C)Pluto
D)Jupiter
22.
The Cassini spacecraft visited which planet? 4.d
A)Pluto
B)Venus
C)Saturn
D)Uranus
23.
The rotation axis of which planet is tilted nearly parallel to the plane of its orbit around the Sun? 4.e
A)Neptune
B)Uranus
C)Pluto
D)Mercury
24.
What does the strength of the gravitational force between two objects depend on? 4.e
A)The volumes of the objects.
B)The sizes of the objects and the distance between them.
C)The densities of the objects.
D)The masses of the objects and the distance between them.
25.
What is one light year? 4.c
A)the distance light travels in one year
B)the distance from Earth to the Sun
C)the distance the Sun travels in one year
D)the diameter of an average star
26.
What force causes a planet to move in an elliptical orbit? 2.g
A)The gravitational force exerted by the Sun on the planet.
B)The gravitational force exerted by the planet on the Sun.
C)The gravitational force exerted on the planet by the planet's moons.
D)The gravitational force exerted on the planet by long-period comets.
27.
A lunar eclipse occurs when _______. 4.d
A)the Sun moves into Earth's shadow
B)Earth moves into the Moon's shadow
C)The Moon moves into the Sun's shadow.
D)the Moon moves into Earth's shadow
28.
What is Kepler's First Law? 4.e
A)The period of revolution increases as the distance from the Sun decreases.
B)Objects in the solar system move around the Sun in elliptical orbits.
C)The period of rotation increases as the distance from the Sun increases.
D)Objects in the solar system move around the Sun in circular orbits.
29.
Which planet has the most moons? 4.e
A)Neptune
B)Saturn
C)Uranus
D)Jupiter
30.
Which star has the highest surface temperature? 4.b
A)red star
B)blue star
C)white star
D)yellow star
Grade 8
Glencoe Online Learning CenterScience HomeProduct InfoSite MapContact Us

The McGraw-Hill CompaniesGlencoe

Please read our Terms of Use and Privacy Policy before you explore our Web site. To report a technical problem with this Web site, please contact the Web Producer.