What is the source of most of the continent's electricity ?
the answers
natural gas
hydro power
nuclear power
petroleum

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

Answerdistinguish between the mercalli scale and the richter scale;