Free points
Who is stronger 1 or 2 (my girl friend's number 2 in pic 1)
or 2nd pic

It looks like the girl in the grey has bigger abs.

You mean who look stronger because the first one is old pic but I’ll say your friend.

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