19 K 39.098

Potassium

alkali metal

Properties

Atomic number
19
Atomic mass
39.098 u
Category
alkali metal
Group
1
Period
4
Block
s-block
State (room temp)
Solid
Outer-shell electrons
1
Electronegativity
0.82 (Pauling)
Density
0.862 g/cm³
Melting point
63.55 °C
Boiling point
758.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

Noble-gas shorthand: [Ar] 4s¹

Electrons per shell: 2, 8, 8, 1, which is 1 in the outermost shell.

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

K
Bohr model; outer-shell electrons in blue

About Potassium

Potassium is a chemical element with symbol K (derived from Neo-Latin, kalium) and atomic number 19. It was first isolated from potash, the ashes of plants, from which its name is derived. In the Periodic table, potassium is one of seven elements in column (group) 1 (alkali metals):they all have a single valence electron in their outer electron shell, which they readily give up to create an atom with a positive charge - a cation, and combine with anions to form salts.

Potassium: frequently asked questions

What is Potassium?
Potassium (K) is the chemical element with atomic number 19. It is a metal: specifically an alkali metal.
What is the atomic number of Potassium?
Potassium's atomic number is 19, which means every Potassium atom has 19 protons in its nucleus.
What is the electron configuration of Potassium?
The electron configuration of Potassium is 1s2 2s2 2p6 3s2 3p6 4s1 (noble-gas shorthand: [Ar] 4s1). Its electrons are arranged in shells of 2, 8, 8, 1, with 1 in the outermost shell.
Is Potassium a metal or a nonmetal?
Potassium is a metal: specifically an alkali metal.
What group and period is Potassium in?
Potassium is in group 1 and period 4 of the periodic table.
Is Potassium a solid, liquid, or gas?
At room temperature, Potassium is a solid.

Position in the periodic table

Open the interactive periodic table →

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