109 Mt 278

Meitnerium

unknown, probably transition metal

Properties

Atomic number
109
Atomic mass
278 u
Category
unknown, probably transition metal
Group
9
Period
7
Block
d-block
State (room temp)
Solid
Outer-shell electrons
2
Electronegativity
-
Density
37.4 g/cm³
Melting point
-
Boiling point
-

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d⁷

Noble-gas shorthand: [Rn] 5f¹⁴ 6d⁷ 7s²

Electrons per shell: 2, 8, 18, 32, 32, 15, 2, which is 2 in the outermost shell.

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

Mt
Bohr model; outer-shell electrons in blue

About Meitnerium

Meitnerium is a chemical element with symbol Mt and atomic number 109. It is an extremely radioactive synthetic element (an element not found in nature that can be created in a laboratory). The most stable known isotope, meitnerium-278, has a half-life of 7.6 seconds.

Meitnerium: frequently asked questions

What is Meitnerium?
Meitnerium (Mt) is the chemical element with atomic number 109. It is not yet firmly classified; it is listed as "unknown, probably transition metal".
What is the atomic number of Meitnerium?
Meitnerium's atomic number is 109, which means every Meitnerium atom has 109 protons in its nucleus.
What is the electron configuration of Meitnerium?
The electron configuration of Meitnerium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d7 (noble-gas shorthand: [Rn] 5f14 6d7 7s2). Its electrons are arranged in shells of 2, 8, 18, 32, 32, 15, 2, with 2 in the outermost shell.
Is Meitnerium a metal or a nonmetal?
Meitnerium is not yet firmly classified; it is listed as "unknown, probably transition metal".
What group and period is Meitnerium in?
Meitnerium is in group 9 and period 7 of the periodic table.
Is Meitnerium a solid, liquid, or gas?
At room temperature, Meitnerium is a solid.

Position in the periodic table

Open the interactive periodic table →

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