Tm
Thulium · element 69
Lanthanide · Solid at room temperature
Thulium is a chemical element with symbol Tm and atomic number 69. It is the thirteenth and antepenultimate (third-last) element in the lanthanide series. Like the other lanthanides, the most common oxidation state is +3, seen in its oxide, halides and other compounds.
Key facts
Atomic mass
168.934222 u
how heavy one atom is
Phase (room temp.)
Solid
Density
9.32 g/cm³
how tightly packed it is
Melting point
1818 K (1545 °C)
when solid turns to liquid
Boiling point
2223 K (1950 °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
1.25
how strongly it pulls electrons
Electron configuration
[Xe] 4f13 6s2
where its electrons live
Shells
2 · 8 · 18 · 31 · 8 · 2
electrons in each layer, inside to out
Discovered by
Per Teodor Cleve
who found it
Appearance
silvery gray
what it looks like
Source: Wikipedia