Discovery: period 4sp
This gives the date, where known, of the discovery of the element, together with the discoveror and place of discovery.
Ref. 2 is a comprehensive volume on the discovery of the elements.
- D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
- M.E. Weeks and H.M. Leicester in Discovery of the elements, J. Chem. Ed, Easton, Penn, USA, 1968.