What is a tip to remember which elements are those that natural appear in nature as diatomic molecules?
There are 7 of these elements.
On the periodic table, draw a 7 with the elements starting with Nitrogen and moving until Fluorine, then move down to Iodine. This forms a 7, although only six are included. Hydrogen is the odd-man-out all by itself in the top left corner, which is also diatomic.
All of these together make 7 elements that are naturally diatomic.