Which of the following is true of atoms in the Universe?
A) Most of the iron in your body was produced by nuclear fission reactions.
B) Most of the calcium atoms in your bones were not assembled inside stars.
C) The iodine atoms were not formed during the violent deaths of rare massive stars.
D) The gold and silver atoms were created in a few moments during supernova explosions.
Question 2
Astronomers try to reconstruct our Galaxy's past from _____.
A) its spherical component
B) its disk component
C) its spiral arms
D) the stars of neighboring galaxies