When a chemical change takes place with the release of heat energy, it is said to be a/an _______ reaction.
Endothermic
Electrochemical
Exothermic
Thermal
When a chemical change takes place with the release of heat energy, it is said to be an exothermic reaction.
There will be some change in mass when a chemical reaction takes place.
In a reversible chemical change, the reverse reaction is releasing heat energy in surrounding. The forward reaction must have been ______________