"De studerende lærer mange forskellige formler i kemi."
Translation:The students learn many different formulas in chemistry.
And copied from there: " 'Studerende' is an adjective-turned-noun. It comes from 'at studere' (to study) and means 'the studying (person)'. Thus it is treated like an adjective, and adjectives don't have the -n suffix. 'The student(s)' therefore is 'den studerende' or 'de studerende', respectively."