Answer:
Step-by-step explanation:
Heat is a reactant.
If the equation requires heat to occur, the reaction is endothermic
The equation would have this model
A + B + heat =====> C + D
If the equation gives away heat, then it is exothermic
The equation would look like this. (I'll use a common reaction)
CH4 + 2O2 - heat ===> CO2 + 2H2O
The heat is minus when it has to be given away.