65 Tb 158.925

Terbium

lanthanide

Properties

Atomic number
65
Atomic mass
158.925 u
Category
lanthanide
Group
f-block
Period
6
Block
f-block
State (room temp)
Solid
Outer-shell electrons
2
Electronegativity
1.1 (Pauling)
Density
8.23 g/cm³
Melting point
1355.85 °C
Boiling point
3122.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁹

Noble-gas shorthand: [Xe] 4f⁹ 6s²

Electrons per shell: 2, 8, 18, 27, 8, 2, which is 2 in the outermost shell.

Related: electron configuration, the Bohr model, valence electrons.

Tb
Bohr model; outer-shell electrons in blue

About Terbium

Terbium is a chemical element with symbol Tb and atomic number 65. It is a silvery-white rare earth metal that is malleable, ductile and soft enough to be cut with a knife. Terbium is never found in nature as a free element, but it is contained in many minerals, including cerite, gadolinite, monazite, xenotime and euxenite.

Terbium: frequently asked questions

What is Terbium?
Terbium (Tb) is the chemical element with atomic number 65. It is a metal: specifically a lanthanide.
What is the atomic number of Terbium?
Terbium's atomic number is 65, which means every Terbium atom has 65 protons in its nucleus.
What is the electron configuration of Terbium?
The electron configuration of Terbium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f9 (noble-gas shorthand: [Xe] 4f9 6s2). Its electrons are arranged in shells of 2, 8, 18, 27, 8, 2, with 2 in the outermost shell.
Is Terbium a metal or a nonmetal?
Terbium is a metal: specifically a lanthanide.
What group and period is Terbium in?
Terbium sits in the f-block (the lanthanide row) of period 6 on the periodic table.
Is Terbium a solid, liquid, or gas?
At room temperature, Terbium is a solid.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.