1) An endothermic process is when heat is put into something or heat is being absorbed.
A. Water boiling
When water boils it is turning liquid into a gas. In order to change a liquid to a gas, it must absorb the heat from its surroundings.
B. Gasoline Burning
The combustion of the gasoline burning releases the heat.
C. Ice forming on a Pond
In order to change a liquid to a solid, it must release the heat to become a solid.
D. Iodine crystals Subliming
To create those types of crystals it is changing its state from a solid to a liquid, absorbong the heat around it.
Since B and C are exothermic (releasing heat). A and D are the correct answers.
Hope this helps ;P
