Inspired by the thread on useless elements.
So I’d like to define the relative use of an element to be a ratio of A and B where :
A = Per annum quantity (weight) used by humans of the element either pure or in a compound.
B = Relative abundance of the element on earth
If we were to take the above ratio, which elements will be on top versus the bottom of the list ? (I am guessing Gold and Platinum to be on top but not sure what will be at the bottom)
By “on Earth”, do you mean the bulk of the planet (including its mostly-iron core), or its crust (which is accessible to humans)?
Either way, I’m guessing that the highest utilization (as you’ve defined it) will be either plutonium or americium. Both have natural abundances so low that they’re usually described as zero, and exist almost entirely as synthesized by humans. There’s a lot more plutonium used, but I don’t know precisely how great either of their effectively-zero natural abundances are, so americium might be enough rarer to make up for that.
thats 91% of earth’s mass from 4 elements. I’m surprised carbon isn’t on that list but I guess not.
As was mentioned, the manmade elements are probably the most utilized.
Also the rare earth elements are probably utilized quite a bit, because they are used to make alternative energy and computing products.
Supposedly earth is facing a helium shortage, so theres that too.
The “rare earths” aren’t actually all that rare. They’re found everywhere in low concentrations. All that’s rare is places where they’re concentrated enough to be economical to mine.
Sure, they’re rare compared to the likes of iron and silicon, but they’re also used in much lower quantities.
Another Wiki page shows (five estimates of) abundance in crust and “annual production.” (Does this “production” figure just refer to production or mining of that element in its elemental form?) Just for fun, I ran this data through the obvious arithmetic to get a sorted list which might be related to OP’s quest … EXCEPT that 33 elements have a blank under “annual production” and another 14 pre-Uranium elements are omitted altogether.
The 14 omitted elements include the noble gases, 6 radioactive elements, and two rare earths. The 33 elements where “production” is blank (shown as “(NP)” below) are a more motley crew: they include several rare earths and other rarish elements, but also important elements like hydrogen, oxygen, carbon, phosphorus, chlorine.
I may as well show the resultant list, as useless as it may be. Highest scoring by OP’s criterion are Nitrogen, Gold and Tellurium! Lowest are Thallium, Silicon, Magnesium.
15.1 81 Tl thallium 60
26.0 14 Si silicon 2
43.1 12 Mg magnesium 7
90.4 4 Be beryllium 48
98.9 32 Ge germanium 53
195.6 39 Y yttrium 30
533.3 23 V vanadium 20
578.9 73 Ta tantalum 52
705.3 13 Al aluminium 3
954.5 38 Sr strontium 16
1161.9 22 Ti titanium 9
1590.6 74 W tungsten 19
1842.1 3 Li lithium 33
3368.4 41 Nb niobium 34
4281.0 49 In indium 68
4920.0 27 Co cobalt 32
7945.5 40 Zr zirconium 18
10167.4 11 Na sodium 6
16326.5 25 Mn manganese 12
20270.2 28 Ni nickel 24
20277.7 33 As arsenic 55
22047.5 26 Fe iron 4
28493.1 46 Pd palladium 74
29111.1 5 B boron 41
32941.7 92 U uranium 51
38270.2 75 Re rhenium 75
44000.0 34 Se selenium 67
44102.5 78 Pt platinum 71
66831.6 80 Hg mercury 66
87777.7 53 I iodine 63
125373.1 50 Sn tin 49
159375.0 30 Zn zinc 25
164141.4 24 Cr chromium 22
168292.6 48 Cd cadmium 64
169024.3 16 S sulfur 17
179210.5 42 Mo molybdenum 54
203292.8 35 Br bromine 59
279136.6 29 Cu copper 26
360000.0 47 Ag silver 65
375460.1 83 Bi bismuth 69
380526.3 82 Pb lead 37
650000.0 51 Sb antimony 62
942857.1 52 Te tellurium 70
1134146.3 79 Au gold 72
4912280.7 7 N nitrogen 31
(NP) 8 O oxygen 1
(NP) 20 Ca calcium 5
(NP) 19 K potassium 8
(NP) 1 H hydrogen 10
(NP) 15 P phosphorus 11
(NP) 9 F fluorine 13
(NP) 56 Ba barium 14
(NP) 6 C carbon 15
(NP) 17 Cl chlorine 21
(NP) 37 Rb rubidium 23
(NP) 58 Ce cerium 27
(NP) 60 Nd neodymium 28
(NP) 57 La lanthanum 29
(NP) 31 Ga gallium 35
(NP) 21 Sc scandium 36
(NP) 62 Sm samarium 38
(NP) 90 Th thorium 39
(NP) 59 Pr praseodymium 40
(NP) 64 Gd gadolinium 42
(NP) 66 Dy dysprosium 43
(NP) 72 Hf hafnium 44
(NP) 68 Er erbium 45
(NP) 70 Yb ytterbium 46
(NP) 55 Cs caesium 47
(NP) 63 Eu europium 50
(NP) 67 Ho holmium 56
(NP) 65 Tb terbium 57
(NP) 69 Tm thulium 58
(NP) 71 Lu lutetium 61
(NP) 44 Ru ruthenium 73
(NP) 77 Ir iridium 76
(NP) 45 Rh rhodium 77
(NP) 76 Os osmium 78
(The 1st column is annual production divided by crust concentration, 2nd is atomic number, 5th is rank order of crust concentration.)
Thank you septimus. I was surprised to see Tellurium.
I think the first part, how much humans use, needs to also be defined a little better. Do we “use” all of the oxygen in the atmosphere, or do we need to calculate how much of is used by humans for respiratory purposes? What about the nitrogen, which we don’t use directly like we do with the oxygen, but which if it wasn’t there we would lose roughly 4/5 of the atmospheric pressure?
ETA. I would guess that argon, at almost 1% of the atmosphere but with little use, would probably be at the bottom of the list.
Nah, argon has a number of uses, including filling the bulbs of incandescent lights to extend their life.
It may be more interesting to talk about isotopes rather than elements. Plutonium-238, for example, can only be manufactured in nuclear reactors, and is in extremely short supply, to the point where NASA had to switch to other power sources for some interplanetary probes. Some other isotopes of plutonium are far more plentiful (relatively speaking).
It’s got some other huge indirect uses because it’s an essential element for plant growth. If it weren’t for nitrogen we wouldn’t anything to eat. Even without losing atmospheric pressure we’d also be pretty screwed if plants couldn’t break up atmospheric CO2 during photosynthesis to create the oxygen in the atmosphere.
It’s so common the ratio probably doesn’t work out well for the OP even if we include those vital indirect contributions.
We need nitrogen, too; we just get it from plants. All proteins contain nitrogen.
The tricky part is that nitrogen really likes to be a gas, as opposed to being a part of some other molecule. It’s hard work to turn atmospheric nitrogen into something that can be used directly in living things, and relatively few organisms are able to do it to any practical degree. All the rest must take advantage of symbiotic relationships with those nitrogen-fixers.
Yes, this. Americium, and AFAIK Plutonium, would have a ratio of 1, as there isn’t ANY of the element that wasn’t manmade and in use (if having been made into an object that is getting used some of the time counts as “in use”). So would Promethium, and probably several other radioactive elements. This is assuming your “B” isn’t based on the natural abundance on earth. If by “B” you mean natural relative abundance, then the ratio might be infinite or so large as to be difficult to estimate.