Are you perplexed or confused by ‘amount of substance’? Don’t feel bad (or stupid). There is nothing to understand for the simple reason that this purported fundamental SI quantity does not exist!
Surprised? Curious? Incensed? Check this!
What is the difference between ‘Avogadro number’ and ‘Avogadro constant’? Which one is equal to 6.022 14 ×1023, and which one is 6.02214 ×1023/mol? or, simply, equal to 1?
Scratch your head, then try this, Sec·2;4i
Did you know that the ‘ideal-gas constant’ R is redundant? What about the Faraday constant?
Oh, no! Don’t tell me what I learned at school is useless! (It is’nt. Just too complicated -Sec·4d,e.)