Which statement is always true when nuclear fusion occurs?
The combined number of protons and neutrons remain constant
The number of protons in the resulting nucleus is less than in each starting nucleus
The total number of protons and neutrons in each nucleus remains constant
The number of protons in the resulting nucleus is double that of a starting nucleus
The total number of protons and neutrons in each nucleus remains constant.
The statement that is always true when nuclear fusion occurs is: The total number of protons and neutrons in each nucleus remains constant.
To find the correct answer, let's first understand what nuclear fusion is and how it affects the nuclei involved.
Nuclear fusion is a process that occurs when two atomic nuclei come together to form a single, more massive nucleus. This process releases a large amount of energy and is the main source of energy in stars, including our Sun.
Now, let's analyze each statement:
1. The combined number of protons and neutrons remain constant.
- During nuclear fusion, the protons and neutrons from the original nuclei combine to form a new nucleus. Since the total number of protons and neutrons is conserved, it remains the same in the resulting nucleus. Thus, this statement is correct.
2. The number of protons in the resulting nucleus is less than in each starting nucleus.
- This statement is generally incorrect because nuclear fusion tends to produce a more massive nucleus by combining the protons and neutrons from the starting nuclei. Therefore, the resulting nucleus usually has more protons than each starting nucleus.
3. The total number of protons and neutrons in each nucleus remains constant.
- This is similar to the first option, and it is also correct. During nuclear fusion, the total number of protons and neutrons in the nuclei involved remains the same. The individual nuclei combine their protons and neutrons to form the new nucleus, while the overall count remains constant.
4. The number of protons in the resulting nucleus is double that of a starting nucleus.
- This statement is not universally true for all cases of nuclear fusion. In some fusion reactions, the resulting nucleus may have a different number of protons, but it is not necessarily twice the amount of the starting nucleus.
Therefore, based on the explanations provided, the correct statement is:
- The total number of protons and neutrons in each nucleus remains constant.