238U has such a long half-life that only half of all of it has decayed into other elements since Earth’s formation
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Technically, using the term “lanthanide” to describe lanthanum is incorrect (since it means “like lanthanum”), but IUPAC considers it to be a lanthanide as a result of common usage.
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Is that the same for actinium and the actinides?
Most of the astatine in the world right now would probably not have existed yesterday, 6 hours ago or even when I first started writing this post.
The most stable isotope of the element is astatine-210 with a half-life of 8.1 hours.
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Yes. Very obvious indeed. I think about this everyday.
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Was this meant to be sarcasm or a genuine response?
Sarcasm.
I don’t even know what astatine is.
Though I’m sure I’m about to get an explanation.
It’s a halogen (group 17, period 6) with atomic number 85 and electronic configuration [Xe] 4f14 5d10 6s2 6p5.
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Bruh. That’s like trying to memorize your Social.
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I learned that in Sophmore year of High School in Chemistry
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Yeah I had Chemistry Sophomore year too.
But we didn’t have to memorize that identification whatever you call it.
Still got a 100% on my final though 
Can’t say the same for bio
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I’d be surprised if you had to. It’s one of the rarest elements in the world and not a lot is known about it.
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*Sophomore.
So electronic subshells and things like that?
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Yeah, I could probably go find my binder and show you a couple assignments from it
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Yes please. May I see them?
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Linus Pauling’s diagram go brrr
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Bruh.
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Not after you corrected his grammar lol
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Im learning this rn sophmore year high school
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