Where did newtonian size setting go in 2.79a I am sure that beside Mass there used to be a particle size and size random setting here in previous versions of blender, but on 2.79a, I can't seem to find it? 

Did I accidentally change a setting somewhere that turned it off  or did they remove it?



I know that I can use the Normal setting under velocity to control the size, but I am not sure how I can make the size random without randomizing the rotation also.
It was "consolidated" under the Render panel in 2.79a

In 2.79, particle size appeared in more than one panel, which caused issues.

See

https://lists.blender.org/pipermail/bf-blender-cvs/2018-January/103452.html

for more details.