33As74.92159
Arsenic
Metalloid
Solid at STP
Period 4Group 15Block PDiscovered Ancient
[Ar]4s2 3d10 4p3
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.
📖 Read more on Wikipedia →Atomic Properties
| Atomic Number | 33 |
| Atomic Mass | 74.92159 u |
| Electron Configuration | [Ar]4s2 3d10 4p3 |
| Oxidation States | +5, +3, -3 |
| Electronegativity | 2.18 (Pauling) |
| Atomic Radius | 185 pm |
| Ionization Energy | 9.815 eV |
| Electron Affinity | 0.81 eV |
| Block | P |
Physical Properties
| Appearance | metallic grey |
| Standard State | Solid |
| Melting Point | 1090 K (816.9 °C) |
| Boiling Point | 887 K (613.9 °C) |
| Density | 5.776 g/cm³ |
| Molar Heat | 24.64 J/(mol·K) |
| CPK Color | #BD80E3 |
Classification
| Category | Metalloid |
| Group Block | Metalloid |
| Period | 4 |
| Group | 15 |
| Block | P |
Discovery
| Year Discovered | Ancient |
| Discovered By | Bronze Age |
| Electron Shells | 2, 8, 18, 5 |