Quiz 7

1. How large is the Sun's radius, compared to the Earth's?
a. Four times larger.
b. 10 times larger.
c. 100 times larger.
d. 100,000 times larger.

2. When we look at a regular, visible-light picture of the Sun, what part of the Sun are we seeing?
a. The core.
b. The corona.
c. The photosphere.
d. The radiation zone.

3. What is the source of all the energy produced in the Sun?
a. Nuclear reactions in the core that fuse hydrogen into helium.
b. Nuclear reactions in the core that convert uranium to plutonium.
c. Chemical reactions that combine oxygen and hydrogen.
d. Gases coming from the core that burn when they reach the surface.

4. What are the features we see as sunspots on the Sun?
a. Places that appear dark because the gas is colder than the rest of the Sun's surface.
b. Holes in the surface of the Sun, through which we can see deep inside it.
c. Places which emit a kind of radiation that is scattered by the Sun's atmosphere.
d. Clouds hovering over the Sun, which prevent us from seeing the surface.

5. How do we know that the Sun rotates?