What would happen if there were no process like weathering and erosion on the Earth's surface?

Then probably we won’t live cause we need rain for plants and we need plants for oxygen and

Cause of he different elevations  hope this ?

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