Identify two factors that can produce metamorphic rocks

Intermolecular bonds become weaker

Melting

Temperature increases

Molecules vibrate faster

Explanation:

In the solid phase, intermolecular forces are found to be strongest. However, as the temperature is increased, the molecules of the solid begin to vibrate faster and intermolecular forces between them begin to weaken.

As intermolecular forces of a substance become weaker, the substance melts. The molecules in the liquid state possesses greater kinetic energy than the molecules in the solid state.

Hence the the answer above.