I'm a returning student and I find a gap in my understanding. I'm not having any luck finding the topic on my own...so any answers or links would be greatly appreciated.
I understand the octet rule...however sulfur and phosphorus often do not always obey the octet rule. My understanding is this has to do with their open D subshells...but what exactly? Why can these (and others I presume) have such a large variety of bond numbers?