What percent of the earth is covered by water? A) 20% B) 50% C) 70% D) 85%

Approximately 71 percent of the Earth's surface is water. : so answer is D

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answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.