What statement is always true when nuclear fusion occurs?
A. The number of protons in the resulting nucleus is less that in each starting nucleus.
B. The total number of protons and neutrons in each nucleus remains constant.
C. The combined number of protons and neutrons remains constant.
D. The number of protons in the resulting nucleus is double that of a starting nucleus.
C. The combined number of protons and neutrons remains constant.
To determine which statement is always true when nuclear fusion occurs, let's consider some basics of nuclear fusion.
Nuclear fusion is a process where two atomic nuclei combine to form a heavier nucleus. This process usually occurs at extremely high temperatures and pressures, such as those found in the core of stars.
Now, let's analyze each statement and understand their validity:
A. The number of protons in the resulting nucleus is less than in each starting nucleus.
This statement is incorrect. In nuclear fusion, the total number of protons is conserved. This means that the resulting nucleus will have the same number of protons as the sum of the protons from the starting nuclei.
B. The total number of protons and neutrons in each nucleus remains constant.
This statement is incorrect as well. In nuclear fusion, while the total number of nucleons (protons + neutrons) is conserved, it is not necessarily constant for each nucleus involved in the fusion. The total number of nucleons in the resulting nucleus may be different from that of the starting nuclei.
C. The combined number of protons and neutrons remains constant.
This statement is correct. During nuclear fusion, the total number of protons and neutrons, which are the nucleons, is conserved. This means that the sum of the protons and neutrons in the starting nuclei will be equal to the sum of the protons and neutrons in the resulting nucleus.
D. The number of protons in the resulting nucleus is double that of a starting nucleus.
This statement is incorrect as well. In nuclear fusion, the number of protons in the resulting nucleus is not determined by a specific factor such as doubling. The outcome depends on the specific isotopes involved in the fusion reaction.
Therefore, the statement that is always true when nuclear fusion occurs is C. The combined number of protons and neutrons remains constant.