Page 5 - Reading Success B9

7. You can conclude that
a. for a core of rock and ice to gain a gas envelope gas particles must come
within its gravitational reach

b. most astronomers have always been dissatisfied with gravitational instability
theory
c. core accretion theory will never be proven true
d. none of the above

8. Which of the following is a fact?
a. Gravitational instability theory is the better theory.
b. Core accretion theory is the better theory.
c. Neither gravitational instability theory nor core accretion theory is a good theory.

d. Gravitational instability theory is the older theory.

9. What is the main purpose of this passage?
a. to describe core accretion theory

b. to discuss the implications of the discovery of a new planet on planet
formation theory
c. to discredit gravitational instability theory

d. to generate interest in astronomy

10. In the context of this passage what does the phrase critical mass mean?
a. the point at which something gains enough mass for something else to happen

b. an extremely judgmental religious sermon
c. careful and exact evaluation of something’s weight
d. the most massive something can become

True or False
Check “T” for true and “F” for false.

1. The newly discovered extra solar planet gives support T F
to gravitational instability theory.

2. The newly discovered planet has approximately the T F
same mass as Saturn.
3. According to core accretion theory planets begin as
T F
small cores of rock and ice.
4. Earth’s core is almost 70 times more massive than T F

the core of the newly discovered planet.
5. The newly discovered planet has a smaller diameter T F
than Saturn.

8_Reading Success B 9