Ask the previous question again in Mango. $regex finds a symbol in the formula string, and one pattern covers both of the GLOB cases: N([^a-z]|$) is N followed by anything but a lowercase letter, or by the end. $not takes a whole selector and keeps the documents it rejects, and it sits beside the other keys with no $and to write. Return the name and formula sorted by name; the same seventy-six compounds come back.
A intermediate exercise, answered in Mango. It is marked by the rows your query returns rather than by how you wrote it, with 3 hints if you want them.
Ask the same question of a chemical dataset in SQL and in Mango and compare the two answers. The database is a SQLite file your browser downloads once and queries locally, so nothing you write ever leaves your machine — which is also why the tool needs JavaScript.