Negative heat of solution means the process if exothermic. More bonds and/or stronger bonds were made compared to the amount of bonds broken. Positive heat oof solution is the opposite, so it is endothermic and etc.
It becomes less negativeTo explain. Lets take a negative, eg -5.If we decrease it by 1, it becomes -6 (where 1 is positive)Thus if we decrease it by -1, it becomes -4 (as the -1 is negative)Note that...
It's just a word-description of the process of adding two negative numbers.It's really easy to do. Just add the two numbers and write the answer witha negative sign.