Al 81 10. Find the ratios of the following pair of angles
(a) 45 and 90%
(b) 254 and 27
fe) 20-30 and 20-25 (d) 20*1020 and 27*15

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

2cool and cold temperature unless its an ever green tree 

Answer they are produced by collision of tectonic plates;

Ithink is a i believe