Which of the following is commonly used to measure distances in space? kilometers the speed of light megameters the speed of sound

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

Answer erosion,oil spills,pollution,tourism,urban development;