Question 1

Which of the following is evidence for the existence of "dark matter" in the universe?

Accepted Answer

A)  The rate of expansion of the universe is speeding up. 
B)  Stars eventually use up their fuel and stop shining. 
C)  The outlying stars around a galaxy appear to orbit more rapidly than expected. 
D)  The space between stars appears dark. C

Question 2

When  undergoes beta-decay, the product is  .

Accepted Answer

A) True 
 B)False  False

Question 3

This type of radiation is released when  .

Accepted Answer

A)  alpha 
B)  beta 
C)  gamma 
D)  All of the answers are correct. A

Question 4

Which of the following correctly balances this decay reaction?

Accepted Answer

A)   
B)   
C)   
D)

Question 5

The larger the apparent magnitude number, the brighter the star appears.

Accepted Answer

A) True 
 B)False

Question 6

If atom X undergoes radioactive decay and becomes atom Y with a half-life of five minutes. After 10 minutes, all number of X atoms have completely turned into to Y atoms.

Accepted Answer

A) True 
 B)False

Question 7

A protostar is a concentrated accumulation of gas and dust in outer space that will become a star.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following correctly balances this nuclear fission reaction?

Accepted Answer

A)   
B)   
C)   
D)

Question 9

The absolute magnitude represents the brightness a star would appear from a standard distance of 32.6 light-years.

Accepted Answer

A) True 
 B)False

Question 10

The Sun's position at noon is best marked by the

Accepted Answer

A)  celestial pole. 
B)  celestial meridian. 
C)  celestial equator. 
D)  All of the answers are correct.

Exam 4: The Universe and Nuclear Reactions

Which of the following is evidence for the existence of "dark matter" in the universe?

When undergoes beta-decay, the product is .

This type of radiation is released when .

Which of the following correctly balances this decay reaction?

The larger the apparent magnitude number, the brighter the star appears.

If atom X undergoes radioactive decay and becomes atom Y with a half-life of five minutes. After 10 minutes, all number of X atoms have completely turned into to Y atoms.

A protostar is a concentrated accumulation of gas and dust in outer space that will become a star.

Which of the following correctly balances this nuclear fission reaction?

The absolute magnitude represents the brightness a star would appear from a standard distance of 32.6 light-years.

The Sun's position at noon is best marked by the