Oh look, Google says a proton is about 1/50th of an inch—roughly the size of a pinpoint! That's only off by a factor of 10 trillion trillion. A proton's actual diameter is around 0.8 femtometers (10-15 meters), not half a millimeter. This is like claiming your coffee molecule is the size of Manhattan.
Next time your undergrad says "but I read it on Google," remember this gem. And they wonder why I drink during office hours.