In 2-3 complete sentences, explain why the moon appears illuminated. Use the "RAP" method to answer this question:

Restate the question
Answer the question
Prove your answer citing textual evidence from the course.

The correct answer is weight.

Asmall proportion of helium in the crust is helium that was trapped in the earth when the earth formed and has not yet escaped. most helium on earth, however, forms as a result of alpha decay of uranium and thorium. the emitted alpha particles, once they grab a couple of stray electrons, become helium atoms and can accumulate in gas reservoirs along with things such as methane.