What determines whether a metamorphic rock is foliated or non-foliated?
the presence or absence of mineral crystals
the water content as a percentage of the rock volume
the number of remaining gas molecules
temperature, pressure, and the original type of rock

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