There's been a previous post about this, and I think the result is they're the same, although maybe "amongst" may be a bit less frequent in everyday talk
The word 'among' came from Old English phrase 'on gemang'. This 'gemang 'was a noun form of 'gemongen' (mingle, gather, crowd, assemble). 'On gemange' was used in the full form before 1000, but it was gradually degraded into 'among' during Late Old English period (1000-1300). In those days 'among' was often used in a genitive form 'amongs' and from about 1400 on some South Englanders began to spe
But as with 'while/whilst', the longer form is sometimes useful when you want a weightier word, for reasons of rhythm, or when 'among' precedes a weak vowel.
"Amongst" is old fashioned, archaic, and pretentious. In the interest of simplification, let's just use "among," for heaven's sake! I think students are just using "amongst" to try to "fancy up" their prose. martha