Metalloid

Arsenic

Arsenic (As) has atomic number 33. PubChem classifies it as metalloid.

Atomic number

33

Symbol

As

Atomic weight (source value)

74.92159

Electron configuration

[Ar]4s2 3d10 4p3

Standard state

Solid

Electronegativity (Pauling)

2.18

Melting point (K)

1090

Boiling point (K)

887

Density (g/cm³)

5.776

Oxidation states

+5, +3, -3

Understanding this entry

Atomic number is the number of protons in the nucleus. Properties are reference values and may depend on conditions and measurement conventions. An atomic weight is not the mass of every isotope. For elements without a standard atomic weight, a source may report an isotope mass number. Blank source values are shown as unavailable rather than estimated.

Further reading and reference: NIH PubChem source dataset ↗. Values and educational summaries are not a substitute for specialised advice.