Which statement describes fusion?

Which statement describes fusion?

• A. Smaller nuclei combine to form larger nuclei
• B. Nuclei split into smaller nuclei
• C. Nuclei decay via beta emission
• D. Atoms exchange electrons

Answer: (A)

Fusion is the process where small nuclei collide and join to form a larger nucleus, releasing energy in the process. This happens because the resulting nucleus has a greater binding energy per nucleon, and the difference in mass (the mass defect) is converted into energy (E = mc^2). A familiar example is hydrogen nuclei fusing in stars to make helium, fueling stellar energy. The other described ideas correspond to different phenomena: splitting a heavy nucleus is fission, not fusion; decay via beta emission is a radioactive decay process; and exchanging electrons refers to chemical interactions, not changes in the nuclei themselves.

Fusion is the process where small nuclei collide and join to form a larger nucleus, releasing energy in the process. This happens because the resulting nucleus has a greater binding energy per nucleon, and the difference in mass (the mass defect) is converted into energy (E = mc^2). A familiar example is hydrogen nuclei fusing in stars to make helium, fueling stellar energy.

The other described ideas correspond to different phenomena: splitting a heavy nucleus is fission, not fusion; decay via beta emission is a radioactive decay process; and exchanging electrons refers to chemical interactions, not changes in the nuclei themselves.