Answer: A
Explanation: The outer part of the bone is called the compact bone.
An example of an exothermic reaction will be formation of ice
Explanation:
When an atom bonds with another atom then it results in the formation of a chemical bond.
This formation of bond could be due to transfer or sharing of electrons.
When a chemical bond is formed due to transfer of electrons then this type of bond is known as ionic bond.
When a chemical bond is formed due to sharing of electrons then this type of bond is known as covalent bond.