Element 68
Erbium
Lanthanides
Erbium (Er) is in the f-block of the periodic table — group 3, period 6.
Erbium is a chemical element in the lanthanide series, with symbol Er and atomic number 68.
Key data
- Atomic number
- 68
- Atomic mass
- 167.259 u
- Group / Period
- 3 / 6
- Block
- f-block
- Phase at STP
- Solid
- Density
- 9.066 g/cm³
- Melting point
- 1528.8 °C
- Boiling point
- 2867.8 °C
- Electron configuration
- [Xe] 4f12 6s2
Periodic table block
Erbium is in the f-block (group 3, period 6). Elements land in the f-block when their highest-energy electrons fill an f subshell — these are the lanthanides and actinides shown beneath the main table.
New to this? Periodic table blocks explained: s, p, d, and f
Common uses
- •Pink optical glass
- •Fiber-optic amplifiers
- •Nuclear control rods
Discovery
Year: 1843
Discovered by: Carl Gustaf Mosander
Frequently asked questions
What is the atomic number of Erbium?
Erbium has atomic number 68. Its symbol is Er and its atomic mass is 167.259 u.
What category of element is Erbium?
Erbium is classified as lanthanides. It sits in group 3, period 6 of the periodic table.
What block of the periodic table is Erbium in?
Erbium is in the f-block (group 3, period 6). Its highest-energy electrons occupy the f subshell — you can see this in its electron configuration, [Xe] 4f12 6s2.
What is Erbium used for?
Common uses of Erbium include: Pink optical glass, Fiber-optic amplifiers, Nuclear control rods.
When was Erbium discovered?
Erbium was discovered in 1843 by Carl Gustaf Mosander.
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