Periodic Table |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
| What is the Periodic Table Showing? | Periodicity |
The INTERNET Database of Periodic Tables
There are thousands of periodic tables in web space, but this is the only comprehensive database of periodic tables & periodic system formulations. If you know of an interesting periodic table that is missing, please contact the database curator: Mark R. Leach Ph.D. The database hold information on periodic tables, the discovery of the elements and elucidation of atomic weights (and more).
| Year: 1895 | PT id = 782, Type = element |
Discovery of Helium
He
Helium, atomic number 2, has a mass of 4.003 au.
Helium is a noble gas, and is the second most abundant element in the universe after hydrogen.
Helium was first observed or predicted in 1868 by P. Janssen and N. Lockyer from solar spectra, and first isolated in 1895 by W. Ramsay, T. Cleve, and N. Langlet.
![]() |
![]() |
![]() |
| What is the Periodic Table Showing? | Periodicity |
© Mark R. Leach Ph.D. 1999 –
Queries, Suggestions, Bugs, Errors, Typos...
If you have any:
Queries
Comments
Suggestions
Suggestions for links
Bug, typo or grammatical error reports about this page,please contact Mark R. Leach, the author, using mark@meta-synthesis.com
This free, open access web book is an ongoing project and your input is appreciated.






