Notes- Lanthanides are also known as "rare earth elements", a deprecated term. Regarding group membership of these elements, see here.
State at standard temperature and pressure (0°C and 1atm)- those numbered in red are gaseous
- those with solid borders are primordial elements, which have stable
isotopes older than the Earth.
- those with dashed borders arise naturally from decay of other elements, and have no isotopes with a half-life comparable to the age of the Earth; however, some are found in trace amounts in radioactive ores.
- those with dotted borders are synthetic elements, which do not occur naturally. Note: Although californium (Cf, 98) does not occur naturally on Earth, Cf and its decay products occur in the Universe; their electromagnetic emissions are regularly observed in supernova spectra.
- those without borders have not been discovered or synthesised yet.
Go to Start | This article uses material from the Wikipedia