Here is a good example of a bad mistake by even an academic text which has been peer-reviewed, but despite that, still confuses students and readers in general. It has been written by academic scholars! as IMAT has been written! So, no one is perfect!
And you can always challenge a mispresented idea or claim by adequate credible reasoning.
I bring this topic because last year there was a very controversial question in the IMAT postulating O2 and N2 are elements!
Still to this date no one could present a text (even non-academic) claiming explicitly that these two formulas (N2 & O2) are elements.
You can call, read and hear them in different texts, papers, lectures, seminars etc. as “elemental oxygen and elemental nitrogen”, “elementary substances of oxygen or nitrogen” (according to IUPAC), “diatomic oxygen or nitrogen”, “dioxygen or dinitrogen” and “oxygen or nitrogen gas”, but never as “elements”, because if they were “elements” in this form, they must have been placed in the periodic table of elements by the same form, showing that they are “elements”. They are elementary substances (IUPAC) made of the same elements. In simpler words, they are substances but not elements.
(element=you cannot make simpler units [not sub-atomic] out of it)
(substance=you can separate the building units [not sub-atomic] of it)
(elementary substance = the building units are elements and they are of the same type, this is why we call the substance “Elementary”, but not an “Element”)
I am still looking forward to seeing any credible text or lecture claiming explicitly that the formulas N2 or O2 are elements.
We have had a very good discussion of this topic in the forum in its time where it was among the breaking incidents of IMAT2023.