Astronomy Quiz Practice

1. Why would two protons combine to form an atom of deuterium (heavy hydrogen) in the core of a star like the Sun? 

• The velocity of protons in the core of the Sun is very large

• The strong nuclear force between protons is not strong enough to overcome the electrostatic repulsion.
• Protons are negatively charged and repel each other, preventing them from combining.
• Deuterium is not formed from the combination of protons in the core of a star.

1. Why does fusion of hydrogen release energy? 

• Hydrogen is a noble gas
• Fusion creates new matter
• The mass of a helium nucleus is smaller than the mass of four protons

• Fusion absorbs energy

1. In the early 20th century, the general opinion among astrophysicist was that the sun derived its energy from

• Gravitational Contraction

• Magnetic fields
• Nuclear fusion
• Solar flares

Energy can be released from elements lighter than iron by

• Nuclear fusion
• Photosynthesis
• Chemical reactions
• Nuclear fission

A temperature of several million degrees is needed to begin the proton-proton cycle because

• To increase the number of electrons
• To reduce the speed of light
• protons are electrically charged

• To create a magnetic field

Which list has the spectral types ordered by decreasing temperature

• O, B, A, F, G, K, M
• A, B, C, D, E, F, G
• Z, Y, X, W, V, U, T
• M, K, G, F, A, B, O

A typical distance between stars in the Solar Neighborhood is roughly ___ light years

• 100
• 2
• 7

• 10

A main sequence star of which spectral type has the lowest luminosity?

• O
• G
• M
• K

A cool giant star has which spectral type?

• M

• A

• B

• G

The Sun has which spectral type?

• A

• F

• K

• G