Question

deep in the core of the sun, 620 million metric tons of hydrogen nuclei are converted into 616 million metric tons of helium nuclei every second. what happens to the missing mass in the suns core?
the missing mass is transformed into energy in a fusion reaction.
the missing mass is transformed into energy in a fission reaction.
the missing mass is converted to heat during an exothermic chemical reaction that produces a new chemical species.
the missing mass is converted to heat during an endothermic chemical reaction that produces a new chemical species.

Explanation:

• Fusion vs. Fission:
• Fusion is the process where light nuclei (like hydrogen) combine to form a heavier nucleus (like helium). In the Sun, hydrogen nuclei fuse. Fission is the splitting of a heavy nucleus, which does not occur in the Sun's core in this context.
• Using Einstein's mass - energy equivalence \(E = mc^{2}\), the "missing mass" (\(\Delta m=620 - 616=4\) million metric tons) is converted into energy.
• Chemical vs. Nuclear Reactions:
• Chemical reactions involve the rearrangement of electrons. Nuclear reactions (fusion in this case) involve changes in the nucleus. The energy production in the Sun is a nuclear (fusion) process, not a chemical reaction (exo - or endo - thermic chemical reactions involve electron - based bonding changes, not mass - energy conversion from nuclear processes).

Answer:

The "missing mass" is transformed into energy in a fusion reaction.