It’s pretty straightforward. You see, each atom needs to gain, lose, or share a certain number of electrons to make a full shell, so likes to bond with that many others.
Except of course transition metals, where by the time they get rid of enough electrons the charge difference makes it more like sharing, which would be gaining electrons, so they end up being indecisive about how many.
Or cases where the atoms just don’t seem to bother like in nitrogen oxides.
Or whatever the heck is going on in boron hydrides like B2H6 and B4H10 and B5H9 with three-center bonds for who knows what reason, you can model it with quantum mechanics but I doubt anyone would have ever called it.
I am so sorry, I got to “…each atom needs to gain, lose…” and started thinking about Duck Dodgers searching for Illudium Phosdex, the shaving cream atom, on Planet X, but his eager young space cadet Porky Pig thinks he’s an idiot, and then Marvin the Martian shows up…
You ever notice how Daffy Duck gets to be in all these cartoons with different characters, but meanwhile Wile E. Coyote is always in a pair? It doesn’t have to be with the Roadrunner, because there’s that one where he’s after Bugs Bunny, but you still never see anything where he has a cadet or Duck! Rabbit! Duck! style rivalry. He only interacts with one other at a time.
That’s because Wile E. has a valency of one, and Daffy can have a valency of more than one.
Don’t know if she still does it by paranormal investigator Susan Blackmore used to keep a random number on top of her fridge, changed weekly. (The number, not the fridge.) Whenever she met someone who claimed to have regular out of body experiences, she’d give them her address and invite them to visit her fridge and email her the number. Last time I heard her tell this story, probably last century, she hadn’t received a single guess.
Yes. Doesn’t even require a full faint. A sudden drop in blood pressure can do it without any loss of consciousness. The explanation I got, probably designed for the layman and perhaps simplistic, is that when blood pressure dropped below a certain threshhold, blood circulation drops for the retina cells furthest from the input point. When those retina cells aren’t getting enough oxygen to send reliable signals, the brain just decides not to trust their input and ignores them, so it only gives you the information from a small circle around the fovea. It is quite unpleasant and I would not recommend the experience to anyone!
The other weird thing is that often full vision doesn’t gradually recover, but rather very suddenly returns to normal but this could be 10 to 30 minutes after blood pressure returns to normal. The retina cells probably do recover gradually, but it’s as if the brain keeps ignoring them, until it suddenly decides it can trust all of them again and brings their signals back online all at once.
Isn’t that a covalent bond? Aren’t valencies only useful for figuring out what happens in ionic bonds?
Oh right, the one where he gets lots of dialog. He had an English academic accent. He also appears with a different accent in a series of cartoons with the sheepdog. The sheepdog and coyote greet each other when they punch their cards at the time-clock each morning, and then retire to different parts of the field to await the siren indicating that the day’s sheep thieving activities can begin. Wile E. is the only character I can remember who has appeared with two different voices, yet is best known for a series in which he cannot speak at all and has to resort to holding up a sign with dialog on it, before being hit by a truck or flattened by a boulder.
You have valences for covalent bonds too, you just can’t figure out compounds directly from them since there are lots of possible arrangements. And Sam Sheepdog is actually paired with Ralph Wolf – they greet each other by name every morning. Besides the voice, Ralph has a different color nose than Wile E.
