To clarify, the range only indicates the "possible values"
of ml (orbitals) , which is based on the value of l. L indicates the subshells s, p, d, f etc., with l = 0 representing s, 1 representing p, and so on. It would be better to visualize this concept by looking at the periodic table. The final valence electron of H and He are both in n = 1, l = 0, ml = 0(1s). Li and Be are in n = 2, l = 0, ml = 0(2s). The final valence electron
of B, C, N, O, F, Ne are all in the 2p subshell l but have different values for ml
B and C are in ml = -1, N and O are in ml = 0, and F and Ne are in ml = 1. Note that there are two electrons in an orbital. You could observe from this pattern that the subshell s(l=0) has 1 orbital(ml=0), and the subshell p has 3 orbirtals(ml = -1,0,or1). Therefore d would have 5 orbitals, and f would have 7, and so on.
Hope this helps!!https://www.google.com/url?sa=i&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FPeriodic_table&psig=AOvVaw0V49vxylHSYabIgugPzGR8&ust=1603768237086000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCKi67bKk0ewCFQAAAAAdAAAAABAD