Two pure substances combine to make a new substance. The new substance cannot be physically separated and has a different boiling point than each of the original substances.
This new substance can best be classified as
an atom
an element
a mixture
a compound

metamorphism is the change of minerals or geologic texture (distinct arrangement of minerals) in pre-existing rocks (protoliths), without the protolith melting into liquid magma (a solid-state change). the change occurs primarily due to heat, pressure, and the introduction of chemically active fluids. i hoped i !

thats not even an aswer choice