It's 1. Melting a substance. The rest are chemical changes
Answer:
You are not showing the question, but I believe the answer is cis-3,4-dimethyl-3-hexene.
Explanation:
since the substituents are on same side, it call cis. Followed by the name.
The primary structure is the amino acids' unique sequence. The polypeptide's local folding to form structures such as the α-helix and β-pleated sheet constitutes the secondary structure. The overall three-dimensional structure is the tertiary structure