A Meteorite That Recently Fell to the EarthEarth Was Found

question 115

Multiple Choice

A meteorite that recently fell to the EarthEarth was found to contain evidence of the existence earlier in its history of a short-lived radioactive isotope of aluminum,²⁶Al,which can be produced only under extremely energetic conditions and in nuclear reactions.What conclusion can be drawn from this observation?

• A) An energetic nuclear event, a supernova, occurred near the Sun, and it produced the ²⁶Al at about the time the meteorite was formed.
• B) The meteorite became so hot on its descent through the EarthEarth''s atmosphere that it became radioactive, and the ²⁶Al was formed at that time.
• C) The meteorite had probably passed through radioactive clouds in space and collected the ²⁶Al before hitting the EarthEarth.
• D) Radioactivity occurs spontaneously in normal matter, so this finding is not surprising.

---

Definitions:

Sarcolemma

The thin, plasmalemma (plasma membrane) surrounding a muscle fiber, crucial for transmitting signals and coordinating contractions.

Lactate

A compound produced during anaerobic metabolism that can be used as a fuel by the heart and other muscles.

Slow Fibers

Slow fibers are a type of muscle fiber that contract slowly and are stamina-oriented, relying on aerobic metabolism for energy, making them resistant to fatigue.

Fast Fibers

Muscle fibers characterized by quick contractions and a capacity for rapid, forceful movements but have lower endurance compared to slow fibers.