Astronomy Chapter Ten

1. The core of the Sun is

At the same temperature and density as the surface.

At the same temperature but denser than the surface.

Hotter and denser than the surface.

Constantly rising to the surface through convection.

Composed of iron.

2. At the center of the Sun, fusion converts hydrogen into

Hydrogen compounds.

Plasma.

Radiation and elements like carbon and nitrogen.

Radioactive elements like uranium and plutonium.

Helium, energy, and neutrinos.

3. How does the Sun generate energy today?

Nuclear fission

Nuclear fusion

Chemical reactions

Gravitational contraction

Gradually expanding in size

4. The phase of matter in the Sun is

Gas.

Plasma.

Liquid.

Solid.

A mixture of all of the above

5. How do human-built nuclear power plants on Earth generate energy?

Chemical reactions

Nuclear fusion

Nuclear fission

Converting kinetic energy into electricity

Converting gravitational potential energy into electricity

6. What processes are involved in the sunspot cycle?

Gravitational contraction of the Sun

Wave motions in the solar interior

Variations of the solar thermostat

The winding of magnetic field lines due to variations in the Sun's rotation

7. Which is closest to the temperature of the core of the Sun?

10,000 K

100,000 K

1 million K

10 million K

100 million K

8. Suppose you put two protons near each other. Because of the electromagnetic force, the two protons will

Collide.

Remain stationary.

Attract each other.

Repel each other.

Join together to form a nucleus.

9. How much mass does the Sun lose through nuclear fusion per second?

4 tons

4 million tons

600 tons

600 million tons

Nothing: mass-energy is conserved.

10. The light radiated from the Sun's surface reaches Earth in about 8 minutes, but the energy of that light was released by fusion in the solar core about

Several years ago.

Tens of years ago.

About a hundred years ago.

About a thousand years ago.

A million years ago.

11. What observations characterize solar maximum?

The Sun becomes much brighter.

The Sun emits light of longer average wavelength.

The Sun rotates faster at the equator.

We see many sunspots on the surface of the Sun.

All of the above