33 As 74.922

Arsenic

metalloid

Properties

Atomic number
33
Atomic mass
74.922 u
Category
metalloid
Group
15
Period
4
Block
p-block
State (room temp)
Solid
Outer-shell electrons
5
Electronegativity
2.18 (Pauling)
Density
5.727 g/cm³
Melting point
-
Boiling point
-

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³

Noble-gas shorthand: [Ar] 3d¹⁰ 4s² 4p³

Electrons per shell: 2, 8, 18, 5, which is 5 in the outermost shell.

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

As
Bohr model; outer-shell electrons in blue

About Arsenic

Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. Arsenic is a metalloid.

Arsenic: frequently asked questions

What is Arsenic?
Arsenic (As) is the chemical element with atomic number 33. It is a metalloid, with properties between metals and nonmetals.
What is the atomic number of Arsenic?
Arsenic's atomic number is 33, which means every Arsenic atom has 33 protons in its nucleus.
What is the electron configuration of Arsenic?
The electron configuration of Arsenic is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3 (noble-gas shorthand: [Ar] 3d10 4s2 4p3). Its electrons are arranged in shells of 2, 8, 18, 5, with 5 in the outermost shell.
Is Arsenic a metal or a nonmetal?
Arsenic is a metalloid, with properties between metals and nonmetals.
What group and period is Arsenic in?
Arsenic is in group 15 and period 4 of the periodic table.
Is Arsenic a solid, liquid, or gas?
At room temperature, Arsenic is a solid.

Position in the periodic table

Open the interactive periodic table →

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