[Big-Daddy]

In general, atoms in Periods 1 or 2 of the Periodic Table obey the octet rule, except for H, He (want 2), Be (wants 4 in its outer shell but is satisfied with 3, and will not have more than 4), B (wants at least 6 in its outer shell, and can have 8 as well but never more). Atoms in Periods 3 and below can exceed the Octet Rule (unlike atoms in Periods 1 and 2); the most commonly encountered of these are P, S, the halogens and perhaps Si.

How accurate is this statement, and where are the mistakes? I want to amend my understanding of the structure-finding process as per these ideas.

Seeing as P has 5 electrons in its outer shell and S has 6, would it be safe to say that P can generally form a maximum of 5 bonds and S a maximum of 6?

Is it also reasonable to say that N atoms, P atoms and the halogens are all fairly likely to form free radicals if they need to (N is the most likely and the halogens least likely of those 3). Al and B could also form free radicals but less likely than any of the 3 above. S and O are unlikely to form free radicals, but if between them O would form the free radical preferentially to S.

How much of this is right, and what are the corrections to make to my understanding? Thank you.