Define it!
The process by which two or more small nuclei fuse to make a bigger nucleus
Nuclear fusion
#1a SG
The earth’s solar system belongs in the Milky Way, which belongs to the Local Group, which belongs to the Virgo Cluster.
True
#23 SG
What is true about the starting mass and ending mass of both nuclear fusion (in the sun) and nuclear fission (in a nuclear power plant) processes?
The starting mass is larger than the ending mass
(mass is converted into energy in both processes)
#7 SG
The term for the distance light could travel along a straight line in one year.
Light year
#1f SG
What part of the sun do we see?
The photosphere
#4 SG
The term for a large ensemble of stars, all interacting through the gravitational force and orbiting around a common center.
Galaxy
#1g SG
The process by which a large nucleus is split into smaller nuclei
Nuclear fission
#1b SG
The crab nebula was most likely formed by a pulsating variable.
False
(it was most likely formed by a supernova, which is an exploding star; supernovas leave behind a cloud of bright gases – called a nebula)
#18 SG
Why is nuclear fusion considered a better option for energy production than nuclear fission?
There are no radioactive byproducts, there is no chance of meltdown, and the starting materials are cheap
#9 SG
Why are Cepheid variables so important for measuring long distances in the universe?
They seem to have a relationship between their period & their magnitude
(this allows them to be used in the apparent magnitude method for measuring long distances in the universe)
#20 SG
Name the four regions of the sun from the inside to the outside.
The core, the radiation zone, the convection zone, and the photosphere
#2 SG
What type of galaxy is the Milky Way?
A spiral galaxy
#21b SG
The amount of isotope necessary to sustain a chain reaction
Critical mass
#1c SG
Of the two methods for measuring the distance from earth to a star (parallax and apparent magnitude methods), the parallax method is the most accurate.
True
#19a SG
Why is it impossible for a nuclear power plant to have a nuclear explosion?
A power plant does not have significantly more than the critical mass of the large nucleus that is breaking apart
#8 SG
Why do most astronomers believe the universe is expanding?
The light from nearly every galaxy experiences a red shift before it reaches the earth
(and the red shift increases the farther the galaxy is from the earth)
#24 SG
How does the sun get its power, and in which region of the sun does this process occur?
The sun gets its power from nuclear fusion that occurs in the core.
#3 SG
What are the four basic types of galaxies?
Spiral, lenticular, elliptical, and irregular
#21a SG
The brightness of a star, corrected for distance, on a scale of -8 to +19. The smaller the number, the brighter the star.
Absolute magnitude
#1d SG
Of the two methods for measuring the distance from earth to a star (parallax and apparent magnitude methods), the apparent magnitude method can be used to measure long distances.
True
#19b SG
Why can’t we use nuclear fusion to produce energy yet?
We cannot master the technology to make it economically feasible.
#10 SG
If the universe is expanding, does the geometry of the expansion matter?
Yes
(the geometry makes a great deal of difference)
#25a SG
What similarity exists between novas, supernovas, and pulsating variables?
They are all variable star types
(their brightness changes radically with time)
#16 SG
Stars group together to form ______, which group together to form _____, which group together to form ______, some of which group together to form ______.
(Fill in using: clusters, galaxies, superclusters, and groups)
Stars group together to form galaxies, which group together to form groups, which group together to form clusters, some of which group together to form superclusters.
#22 SG
The brightness of a star as seen in the night sky. The smaller the number, the brighter the star.
Apparent magnitude
#1e SG
A supergiant star is at:
Magnitude -7
Spectral Letter F
(Confirm this star type on the H-R Diagram on page 421.)
True
#11c SG
Two 4He nuclei collide and turn into a 7Be nucleus and one neutron. Is this nuclear fusion or nuclear fission?
Nuclear fusion
(Since two small nuclei became a bigger nucleus plus a neutron)
#6 SG
Why does the geometry of the expansion of the universe matter?
It is the basis to develop theories about the universe’s formation
(the theories depend on the assumed geometry)
#25b SG
What is the big difference between novas, supernovas, and pulsating variables?
Lifetime
(pulsating stars last a long time, supernovas exist very briefly, and novas are somewhere in between)
#17 SG
Put these stars in order by increasing size – red giant, main sequence, supergiant, and white dwarf.
(hint: pay attention to the names; also see page 408)
White dwarf, main sequence, red giant, and supergiant
#13 SG
This type of star is at:
Magnitude -1
Spectral Letter K
(Find this star type on the H-R Diagram on page 421.)
Red giant
#11a SG
A supergiant star is at:
Magnitude 0
Spectral Letter B
(Confirm this star type on the H-R Diagram on page 421.)
False
(This is a main sequence star, like our sun.)
#11b SG
A 251Cf nucleus is bombarded with a neutron. It breaks down into a 124Sn nucleus, a 120Cd nucleus, and 7 neutrons. Is this nuclear fission or nuclear fusion?
Nuclear fission
(Since a large nucleus split into two smaller nuclei and a few neutrons)
#5 SG
To classify a star, find it on the H-R Diagram on page 421. Its measures are:
Magnitude 11
Spectral Letter B
White dwarf
#11d SG
Of these stars – red giant, main sequence, supergiant, and white dwarf – which is most like our sun? Which is coolest in temperature?
Most like our sun = main sequence
Coolest = red giant
#12 & 15 SG
Put these stars in order by increasing brightness – red giant, main sequence, supergiant, and white dwarf.
(hint: the smaller the magnitude, the brighter the star; also see the H-R Diagram on page 421)
White dwarf, main sequence, red giant, and supergiant
#14 SG