How is enthalpy used to predict whether a reaction is endothermic or exothermic?

A) When the enthalpy of the reactants is higher than the enthalpy of the products, the reaction is endothermic.
B) When the enthalpy of the products is higher than the enthalpy of the reactants, the reaction is exothermic.
C)When the enthalpy change of the reaction is positive, the reaction is exothermic.
D)When the enthalpy change of the reaction is positive, the reaction is endothermic

When the enthalpy of the reactants is higher than the enthalpy of the products, the reaction is endothermic.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

b) nuclear ive learned that in a pedtrodic table