Question

Which change is exothermic?

Rain becomes sleet when the temperature falls below 0°C.

Icebergs shrink as global temperatures rise.

Solid water turns to liquid water as energy is added.

Answer 1

An exothermic change will be when rain becomes sleet when the temperature falls below 0 degree Celcius. An exothermic change or reaction is a chemical reaction that release energy by light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation: Reactants = products +energy. 

Answer 2

Answer:

Rain becomes sleet when the temperature falls below 0°C.

Explanation:

Energy is released in an exothermic reaction and energy is absorbed in an endothermic reaction.  

Option A is exothermic.  Change of rain to sleet occurs at very low temperatures below 0°C with the release of heat.

Option B is endothermic. As the rising temperature causes heat to be absorbed by the iceberg thus melting them.  

Option C is endothermic. Solid to liquid phase change of water occurs with the absorption of heat energy.