Download 2nd 9 weeks Study Guide

2nd 9 Weeks Science Study Guide
1. Nebula- cloud of gas and/or dust in space.
2. Protostar- a collapsing cloud of gas and dust destined to become a star; a
developing star not yet hot enough to engage in nuclear fusion.
3. Main-Sequence Star- a star that falls into the main sequence category on
the H-R diagram; This category contains the majority of stars and runs
diagonally from the upper left to the lower right on the H-R diagram.
4. Red-Giant- a large, cool star of high luminosity; a star occupying the upperright portion of the H-R diagram.
5. Red Supergiant- a very large, very bright red giant star.
6. Planetary Nebula- medium-mass stars are thought to cast off their bloated
outer layer, creating an expanding round cloud of gas. The remaining hot,
central white dwarf heats the gas cloud, causing it to glow. These are often
beautiful, gleaming spherical clouds.
7. Supernova- an exploding star that increases in brightness many thousands
of times.
8. White Dwarf- a star that has exhausted most or all of its nuclear fuel and
has collapsed to a very small size, believed to be near its final stage of
evolution.
9. Black Dwarf- the last stage after a white dwarf must be a small, cold body
that has run out of all of its fuel.
10. Neutron Star- a star of extremely high density composed entirely of
neutrons because the electrons are forced to combine with protons to
produce neutrons.
11. Black Hole- a massive star that has collapsed to such a small volume that
its gravity prevents the escape of everything, including light.
12.Electromagnetic radiation- visible light is a form of:
13. An H-R diagram is a graph of stars temperature and absolute brightness.
14. A low-mass main sequence star will eventually evolve into a white dwarf.
15.A star system in which one star blacks the light from another is called an
eclipsing binary.
16.Astronomers theorize that the universe began in an enormous explosion
called the big bang.
17.The most common chemical element in most stars is hydrogen.
18.The main factor that affects the evolution of a star is its mass.
19.The color of a star is related to its temperature. Blue, white, yellow, redorange, red identifies the temperatures of stars in order from hottest to
coldest.
Use the chart to answer # 20 and 21.
Type of Star:
Main Sequence
Red Giant
Supergiant
White Dwarf
Percentage of Total:
90.75%
0.50%
<0.0001%
8.75%
20.According the table the most common type of stars in the Milky Way is
Main-sequence stars.
21.If there are a total of 400 billion stars in the Milky Way, about how many
white dwarfs are there in the galaxy?
a. 8.75 billion
b. 35 billion
c. 87.5 billion
d. 3,500 billion
22.Patterns of stars in the sky are called constellations.
23.Sound waves are not part of the electromagnetic spectrum.
24.A neutron star that appears to produce pulses of radio waves is called a
pulsar.
25.The earliest stage of a star’s life is called a protostar.
26.The Hertzsprung-Russell diagram graphs stars’absolute brightness and
temperature.
27.How long a star “lives” depends on its mass.
28.Parallax can’t be used on a star if the star is too far away.
29.A light-year is a unit of distance.
30.When the star runs out of fuel, it cannot become a protostar.