I can help but more Context is needed. Like exactly what your looking at for the Melting point, boiling point and the appearance.
Answer:
part a=A. A physical change, then a chemical change
part b:evidence
without physical change any sorts of chemical change do not take place.
for example: when sugar is heated on spoon the physical change takes place in sugar .sugar starts to form liquid from solid.
Diamond is composed of hexagonal rings in which sp3 hybridized carbon atoms are linked together.
Hybridization refers to the mixing of atomic orbitals to yield hybrid orbitals that are suitable for bonding. The energy of orbitals that combine to form hybrid orbitals must be close enough for such combination to take place.
Diamond is composed of hexagonal rings in which sp3 hbridized carbon atoms are linked together. Each carbon atom in diamond is tetrahedral.
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