Examine the photo of a factory’s smokestacks.

Two factory smokestacks emitting smoke.

What direct negative effect does this factory have on the environment?

pollution
urban sprawl
overuse of resources
introduction of nonnative species

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen

Answeroil-shale;