Question 1 (8 points)
a. Fill in the blanks in the following paragraph to correctly describe the nucleus of an atom. (2 points)
and
Are the two types of nucleons that make up a nucleus. The force exists between in the nucleus because of their charge. Because it is repulsive, this force tends to make a nucleus. However, the force acts between protons, between neutrons, and between protons and neutrons. This force helps to make a nucleus, because it is always attractive.
How does the total mass before a nuclear reaction compare with the total mass after a nuclear reaction? How does Einstein’s equation address this difference? (1 point)Complete the table below to review the main types of radiation. (2 points)
| Radiation | Symbol | Mass number |
Charge |
Penetrating
ability |
| Alpha particle | ||||
| Negative beta particle (electron) |
||||
| Positive beta particle (positron) |
||||
| Gamma ray |
Write the symbol for the nucleus that completes each nuclear equation. (1 point each)
Question 2 (4 points)
a. What happens to a radioactive isotope over the course of 1 half-life? (1 point)
How does the half-life of an isotope relate to the stability of its nucleus? (1 point)
Complete the following table to show how to determine the amounts of parent and daughter nuclei and the time passed with each half-life. (2 points)
| Number of half-lives |
Fraction of original isotope remaining |
Fraction of original isotope changed to daughter isotope |
Ratio of parent isotope to daughter isotope |
Time
|
| 0 | 1 | 0 | 1:0 | 0 |
| 1 | 20 days | |||
| 2 | 1:3 | |||
| 3 |
Question 3 (3 points)
a. Review nuclear fission and nuclear fusion by placing X’s in the appropriate boxes. (2 points)
| Nuclear fission |
Nuclear fusion |
|
| Converts matter into energy | ||
| Occurs in nuclear power plants | ||
| Splits a nucleus | ||
| Produces radioactive waste | ||
| Uses hydrogen | ||
| Occurs in the Sun | ||
| Uses uranium | ||
| Creates limited fuel | ||
| Creates abundant fuel |
What conditions are required for nuclear fusion that prevent it from being used to generate electric energy? (1 point)
Question 4 (4 points)
a. In quantum mechanics, what does wave-particle duality describe? (1 point)
What does the term quantized light mean? (1 point)
Fill in the blanks in the following paragraph to correctly identify phenomena that help provide evidence for the particle nature of light. (2 points)
A(n) _______________ absorbs energy and then emits electromagnetic radiation based on its _______________. Classical physics predicted that at a high enough temperature, _______________ light would be emitted. Instead, white light was emitted, resulting in the ultraviolet _______________. The photoelectric effect occurs when light shining on a metal creates a(n) _______________. However, only light of a certain minimum _______________ causes electrons to flow. Gas atoms excited by an electric current emit bands of colors of light in a(n) _______________. Each narrow band of light is associated with _______________ of a specific energy.
Question 5 (3 points)
a. In what frames of reference does special relativity apply? (1 point)
In what frames of reference must general relativity be used? (1 point)
Describe what happens to time and length at speeds close to the speed of light. (1 point)
Question 6 (3 points)
a. Describe the big bang theory. (1 point)
Match each model of the universe with the future it predicts. (1 point)
A. Closed
B. Flat
C. Open
The universe will stop expanding but will not collapse.
The universe will continue to expand forever.
The universe will stop expanding and then collapse back to its point of origin.
Match each observation to the conclusion it supports in the big bang theory. (1 point)
A. Light from other galaxies is shifted toward the red end of the spectrum.
B. Cosmic background radiation appears uniform across the sky.
C. The amount of helium in the universe matches predictions.
Nucleosynthesis of light elements occurred shortly after the expansion of the original ball of energy.
The universe is expanding.
The universe began from a single point.
