Interesting! Shame it's so quick in places, there's a lot of history in some of it.
I'd note that, even though cooper and gold etc. were known to the ancients, we didn't have the concept of elements until John Dalton's theory around 1800 or so, so it's a bit of a cheat to describe them as 'known elements'. I suspect that they knew they needed to breathe and couldn't do so underwater, too, even though water contains more oxygen than air. Just because you know something exists, doesn't mean you understand it.
Tempting fate to label the table as 100% full at 118 elements, too. There's no particular quantum mechanical reason that we know of to stop there, that I know of, anyway - another row with properties predicted by their columns seems more likely?