The answer would be A and E
(I explained on the other one)
Answer:
a. bubbles formed
Explanation:
Bubbles are a sign of gaseous molecules escaping, meaning that something has forced molecules to break apart and escape. A chemical reaction involves any change that directly impacts the molecular formation of a substance.
Heat & Pressure ( So I guess in this answer choices it's " Heat up" )
The reason it's not " melt " because if melting were to take place then that would make Magma, and magma isn't metamorphic rock.
Variables is likely the correct answer.
Id hav to go with A,reason i say that is, synthetic is man made..so it could b altered at anytime
