Answer
Exothermic
Step-by-step explanation
Mg + H2S04 ----> MgSO4 + H2 + HEAT
In an endothermic process, the system gains heat (heat added to the reactant side of the equation) from the surroundings and so the temperature of the surroundings decreases.
A chemical reaction is exothermic if heat is released by the system (heat added on the product side of the equation) into the surroundings.
Hence, the given equation has heat added on the product side indicating that the reaction is classified as exothermic.