Why "лук" is a mass noun while "огурец" is not?

Question

In Russian, we use some fruit and vegetable names as mass nouns and don't form plural for them:> * Салат с луком / капустой / клубникойwhile the others do form plural:> * Салат с огурцами / кабачками / артишоками / помидорамиAlso, if you ask someone:> Что у тебя в сумке?then the answer:> У меня в сумке огурец / кабачок / баклажан / артишокwould unequivocally mean there's exactly one vegetable in the bag, while this answer:> У меня в сумке лук / капуста / клубникаmay mean any quantity.What makes some vegetable names form the plural and the others not?

Answer 1

Because лук / капуста / клубника are uncountable nouns like "candy" is in English.

If you want ONE - you will ask for a piece of candy. But you will want one whole cookie you will ask for one cookie, not for a piece of one.

If you want one of лук you will ask - одну луковицу, одну головку капусты, одну ягоду клубники.