Which statement describes conditions in which a mineral can form? A. Crystals of minerals dissolve in the groundwater in caves.
B. Molten materials are cooled in a metalworks factory.
C. Materials are mined from deposits deep underground,
D. Materials dissolved in seawater crystallize on an ocean bottom.

The comparison of the number of atoms in a copper coin the size of a penny with the number of people on earth is made to illustrate which of the following? a. that atoms are indivisible b. that atoms are very small c. that atoms are very large d. that in a copper penny, there is one atom for every person on earth