I am confused by the usage "Kr-33" in the main article on Krypton:

In 1960 it was internationally agreed that the fundamental unit of length, the metre, should be defined as 1 m = 1,650,763.73 wavelengths (in vacuo) of the orange-red line of Kr-33.

What does the 33 refer to?

Environmental Pollution and Public Health (EPPH 2009),
Special Track within iCBBE2009
Call for Papers
http://www.icbbe.org/epph
Beijing, China, June 11-13, 2009
==================================================================
This special track EPPH is part of the third international conference
on Bioinformatics and Biomedical Engineering (iCBBE2009). EPPH2009
focuses on the relationship between environmental pollutions and human
health problems. The conference is sponsored by IEEE Engineering in

Nuclear particle realy it is possible reduce carbon dioxide emissions, because the carbon is a power elecrophile. For example, sodium peroxide is a nuclearphile:
Na2O2+CO2=Na2CO3 + O2

Hello-
I'm looking for a vintage, large scale, periodic table to purchase and was referred to your website via search engine in the process. I've been looking for some time and am having trouble finding one. If you know of any sources, would you take a moment to contact me at scottbnichols@live.com please?
Thank you.

Dear All,

With Firefox browser running in Windows the number of bars (beside text "atomic number" describing electrons in electron levels graphics in Atom properties/ Electron shell properties is incorrect.

For instance for carbon I see 4 bars instead of 6.

Or have I misunderstood something?

Terveisin, Markus

Hi there, I am new to the group and look forward to learning. I was reading about the periodic table and trying to figure if there are different tables. I read the Element 56 was Lanthium and 57 was Cerium. Could this be correct or a mistake. The document was quite old.

Also is there a formula to convert the F and C melting and boiling point to the Kelvin scale?

Kindest regards,
Mary.

Add another Use that has often been referenced. Helium is used as a mix with air in scuba tanks for deep dives to lessen the proportion of oxygen.

See this link:
http://www.pa.msu.edu/sciencet/ask_st/082593.html

Thanks for the great web page - SCSmith

How to writing electronic configurations: Lantanum and Actinium, in WebElements Periodic Table?

http://www.egregoralfa.republika.pl/english/newtable.html
There The new Arrangement is of chemical elements. What about that do you think?

Posted April 15th, 2008.
It appears there is a mistake in the values of Young's
modulus (E) and bulk modulus (K) for Rhodium.

First, the Poisson's ratio (nu) value of 0.26 matches
that of a standard source, ASM Metals Handbook. The value
for Young's Modulus E, stated in that source is 379 GPa. Any
standard text on mechanics of materials will confirm the
relationship K = E / {3(1-2*nu)} . This relation shows that
for Poisson's ratio less than 1/3, K must be less than E.
If E=379 GPa and nu=0.26, then we should have
K=E/1.44=263.2 GPa.