Er
Erbium · element 68
Lanthanide · Solid at room temperature
Erbium is a chemical element in the lanthanide series, with symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements on Earth. As such, it is a rare earth element which is associated with several other rare elements in the mineral gadolinite from Ytterby in Sweden, where yttrium, ytterbium, and terbium were discovered.
Key facts
Atomic mass
167.2593 u
how heavy one atom is
Phase (room temp.)
Solid
Density
9.066 g/cm³
how tightly packed it is
Melting point
1802 K (1529 °C)
when solid turns to liquid
Boiling point
3141 K (2868 °C)
when liquid turns to gas
Period
6
its row in the periodic table
Group
3
its column in the periodic table
Block
F-block
the neighbourhood it lives in
Electronegativity
1.24
how strongly it pulls electrons
Electron configuration
[Xe] 4f12 6s2
where its electrons live
Shells
2 · 8 · 18 · 30 · 8 · 2
electrons in each layer, inside to out
Discovered by
Carl Gustaf Mosander
who found it
Appearance
silvery white
what it looks like
Source: Wikipedia