33 - Arsenic metalloid
Discovered by Bronze Age in 1250
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.
Periodic table
| Shell | Electrons | Orbitals |
|---|---|---|
| 1 | 2 | 2 in 1s |
| 2 | 8 | 2 in 2s + 6 in 2p |
| 3 | 18 | 2 in 3s + 6 in 3p + 10 in 3d |
| 4 | 5 | 2 in 4s + 3 in 4p |
Electron shells
metallic grey Appearance
74.9 u Atomic Mass
1.15 Å Atomic Radius
887 K Boiling Point
15 Group
-3, 3, 5 Common Oxidation States
1.19 Å Covalent Radius
5.73 g/cm³ Density
77.7 kJ/mol Electron Affinity
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3 Electron Configuration
[Ar] 3d10 4s2 4p3 Electron Configuration (semantic)
2.18 Electronegativity
33 Electrons
9.79 eV First Ionization Energy
-3, -2, -1, 2, 3, 5 ICSD Oxidation States
947, 1798, 2735, 4837, 6043, 12310 kJ/mol Ionization Energies
1.09k K Melting Point
89 Mendeleev Number
24.6 J/(mol·K) Molar Heat
4 Number of Shells
5 Electron Valency
42 Neutrons
33 Atomic Number
14 Number of Isotopes
-3, 2, 3, 5 Oxidation States
4 Period
Solid Phase
33 Protons
2, 8, 18, 5 Electron Shell Occupations
0.329 J/(g K) Specific Heat