Can all sedimentary environments be differentiated by the size and shape of their grains? which environments are distinctive, and which are not

How am i supposed to know your lecture

Don’t use up to much of them it leads to pollution

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