I saw a problem right away with elements on the Actinide Decay Series that ends in Pb. It is that the abundance of At, and Fr seem much too big in accordance with how much of these elements have ever been isolated. A way to reconcile this is to argue that these elements are produced as fast, but decay as rapidly as to justify the relative abundances shown, or the abundances are over estimated and wrong. Comment?
Oh really! Where is this place, where platinum is half as common as hydrogen?
A second comment is that physical conditions and geochemistry on the earth’s surface bias these estimates somewhat. In the visible matter of the rest of the Universe H is about 74% and He about 23% leaving all the rest, called “Metals” by the astronomers. Of these the most abundant reflect the most stable nuclii, but we are still seeing fractionation due to the differentiation of the earth into core, mantle and crust. There is probably much more Fe and Pt group and heavy metals in the core and mantle than there is in the crust, an in fact there may be what we see of heavy metals like Au and Pt group in the crust may be largely due to asteroid impacts after the earth differentiated and the crust cooled, brought here during the Late Bombardment.
Is this abundance on Earth or abundance in the cosmos?
I wondered too–the figure legend says Earth, and that other planets are likely different.
Yttrium is surprisingly abundant. In high school chemistry class we had to pick an element and do a report on it. At the time my only source of information was an old encyclopedia, and I had a hard time stretching “There are no known uses for this element”. It’s got a few more uses these days.
It’s log, it’s log, it’s big, it’s heavy, it’s wood.
It’s log, it’s log, it’s better than bad, it’s good.
The legend doesn’t indicate whether “abundance” means by atoms or by mass. For examples, if there were 5 hydrogen atoms and 5 lead atoms, you could say there are equal amounts of hydrogen and lead; however, if you calculate this by mass, there is way more lead than hydrogen (because a single lead atom is much heavier than a single hydrogen atom). Other, more recent studies of this put Oxygen and Silicon way ahead of the pack, and not Hydrogen and Carbon, as this graphic does. For example, see Figure 4 here: http://pubs.usgs.gov/fs/2002/fs087-02/
Oh yeah. Astatine is the thing that should not be, yet it’s shown as substantially more abundant than Radon–a gas that’s abundant enough to cause health problems.
As wikipedia notes
Elemental astatine has never been viewed, because a mass large enough to be seen (by the naked human eye) would be immediately vaporized by the heat generated by its own radioactivity. Astatine may be dark, or it may have a metallic appearance and be a semiconductor, or it may even be a metal… Three years later it was found in nature, although it is the least abundant element in the Earth’s crust among the non-transuranic elements, with a total existing amount of much less than one gram at any given time.[4]
There are few discussions that can’t be greatly improved by timely invocation of Log.
They are in secular equilibrium with their parent nuclide (the uranium & thorium decay series) – a steady-state concentration.
I learned about YAG lasers when I was a kid, but haven’t paid much attention to yttrium since then. Time to hit Wikipedia. 
You can use it in Scrabble?
I believe yttrium is used in the creation of suicide nets used around factories.
Look at the YAG itself too. It’s a host crystal for many kinds of dopings. The Ce:YAG is commonly encountered in white LEDs. (And a Nd:YAG (alternatively Nd:YVO4) laser crystal can be found in those green laser pointers, mated with a nonlinear optical material. Those humble little thingies are quite complex electrooptics.)
Then there’s the YIG, where there’s iron instead of aluminium; look for that one for its interesting microwave and magnetic properties/uses. Not sure how easy is that one to find in the wild.
Not even log, bro.
e^4 << H/Pt.
It’s poetic license, at best.
How can you do poetry, and not appreciate musical comedy? Sigh.
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