Update your periodic tables

[clıppy]

It's official. They've changed the standard atomic weights for 19 elements on the periodic table.
IUPAC Announcement
Popsci article

The following changes in the standard atomic weights have been made:

aluminium (aluminum): from 26.981 5386(8 ) to 26.981 5385(7)

arsenic: from 74.921 60(2) to 74.921 595(6)

beryllium: from 9.012 182(3) to 9.012 1831(5)

cadmium: from 112.411(8 ) to 112.414(4)

caesium (cesium): from 132.905 4519(2) to 132.905 451 96(6)

cobalt: from 58.933 195(5) to 58.933 194(4)

fluorine: from 18.998 4032(5) to 18.998 403 163(6)

gold: from 196.966 569(4) to 196.966 569(5)

holmium: from 164.930 32(2) to 164.930 33(2)

manganese: from 54.938 045(5) to 54.938 044(3)

molybdenum: from 95.96(2) to 95.95(1)

niobium: from 92.906 38(2) to 92.906 37(2)

phosphorus: from 30.973 762(2) to 30.973 761 998(5)

praseodymium: from 140.907 65(2) to 140.907 66(2)

scandium: from 44.955 912(6) to 44.955 908(5)

selenium: from 78.96(3) to 78.971(8 )

thorium: from 232.038 06(2) to 232.0377(4)

thulium: from 168.934 21(2) to 168.934 22(2)

yttrium: from 88.905 85(2) to 88.905 84(2)

[clıppy]

I hate to sound blunt, but most of us could not care less unless VCAA said something about it.

The government could discover that oxygen is not an actual element, but as long as VCAA say it is, that's all I (and most ANers) are concerned about

It's still a little bit interesting though

[BasicAcid]

It's still a little bit interesting though

Actually yeah, I'll have to agree haha.

Did they recalibrate their mass spectrometers or something?

[Alwin]

I care.

[Jeggz]

I care.

HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA.
Second time I fell of my chair, thanks to you 

[Alwin]

Did they recalibrate their mass spectrometers or something?

Chemistry's Biggest Loser: Official Atomic Weights Change For 19 Elements

The changes in weights mostly come from continuing improvements in atomic mass measurements, including advances in the technology behind mass spectrometers. But it's not all about measuring more accurately. For one of our biggest losers, thorium, the IUPAC decided to recognize an isotope, thorium-230, that it previously thought was too rare to include in atomic weight calculations.

The last time international chemistry agencies really altered the periodic table was in 2009, when IUPAC decided to list the atomic weights of some elements as ranges, instead of single numbers. The change affected a number of low-mass elements, such as hydrogen, nitrogen, carbon and sulfur. The ranges show students the possible atomic weights for each element, which can vary depending on the origin of the element. You can print a copy of the IUPAC's peroidic table for free.

"We wanted to let high school students and college students know that atomic weights are not constants of nature," says Tyler Coplen, a U.S. Geological Survey chemist who works on isotopes research and official atomic weights changes. "This is the way we did that, by giving them interval atomic weight values."

[lzxnl]

How many of us know much about half of those elements there? All I know what to do with yttrium is find it in the periodic table and figure that it'll predominantly exist in the +3 oxidation state.