Arsenic (As) — Element 33: Properties & Data | Aladdin Scientific
Arsenic(As) — Element 33
Arsenic (As) is a metalloid with atomic number 33 and atomic mass 74.9216. It has melting point 1090 K (817 °C), boiling point 887 K (614 °C), density 5.776 g/cm³. It sits in group 15 and period 4 of the periodic table and has been known since antiquity.
Key facts
| Atomic mass | 74.9216 u |
|---|---|
| Electron configuration | [Ar]4s2 3d10 4p3 |
| Oxidation states | +5, +3, -3 |
| Electronegativity (Pauling) | 2.18 |
| Atomic radius (van der Waals) | 185 pm |
| Ionization energy | 9.815 eV |
| Electron affinity | 0.81 eV |
| Melting point | 1090 K |
| Boiling point | 887 K |
| Density | 5.776 g/cm³ |
| Standard state | Solid |
| Year discovered | Ancient |
Frequently asked questions
What is the electron configuration of arsenic?
The ground-state electron configuration of arsenic is [Ar]4s2 3d10 4p3.
What group and period is arsenic in?
Arsenic (As) is in group 15 and period 4 of the periodic table, classified as a metalloid.
What is the melting point of arsenic?
Arsenic melts at 1090 K (817 °C).
What is the standard state of arsenic?
Arsenic is a solid at standard temperature and pressure.
Related elements
About this data: property values compiled from IUPAC Standard Atomic Weights (2021), the NIST Atomic Spectra Database, and PubChem. Curated by the Aladdin Scientific technical team. Last reviewed: .