What are physical boundaries? *

A) boundaries that are physical features such as mountains and rivers

B) imaginary lines created by governments

C) boundaries that are drawn on the ground

D) none of the above

A

Explanation: The answer is A because a physical boundary is a naturally occurring barrier two areas. This includes rivers, mountain ranges, oceans, and deserts.

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

The peak above is part of the  sierra madre occidentals ,  a chain of volcanic mountains that runs through the middle of central america.