I didn't know that, but that makes sense. And magnesium is resolutely divalent, while iron, manganese, and cobalt are happy enough to be divalent, and nickel,

I didn't know that, but that makes sense. And magnesium is resolutely divalent, while iron, manganese, and cobalt are happy enough to be divalent, and nickel, while not as stuck-up as magnesium, strongly prefers it. BTW, if you haven't seen it, you'll probably be interested in https://news.ycombinator.com/item?id=44698409 https://news.ycombinator.com/item?id=44698409.