1. Which statement is always true when nuclear fusion occurs?

A. The number of protons in the resulting nucleus is less than in each starting nucleus.

B. The number of protons in the resulting nucleus is double that of a starting nucleus.

C. The combined number of portions and neutrons remains constant.

D. The total number of protons and neutrons in each nucleus remains constant.

•

2. Use the equation to answer the question.
2H + 2H—> 4H + energy
1 1 2

Which statement best describes the mass numbers of the atoms in the reaction?

A. There are two atoms with mass numbers of 2.

B. There is one atom with
a mass number of 2.

C. There are two atoms with mass numbers of 1.

D. There is one atom with a mass number of 1.

•

3. How is the mass number calculated for an atom involved in nuclear fusion?

A. It is the number of electrons.

B. It is the number of protons plus electrons.

C. It is the number of neutrons.

D. It is the number of protons plus neutrons.

•

4. Which change will always take place in nuclear fusion?

A. The total charge will be less than before the fusion took place.

B. The nucleus with a smaller mass than any of the reactants will be produced.

C. A nucleus with a greater mass than any of the reactants will be produced.

D. The total charge will be greater than before the fusion took place.

•

5. Which statement best summarizes the way the sun produces energy?

A. Combustion reactions in the sun release large amounts of chemical energy.

B. Fusion reactions in the sun release large amounts of chemical energy.

C. Combustion reactions in the sun convert small amounts of matter into large amounts of energy.

D. Fusion reactions in the sun convert small amounts of matter into large amounts of energy.