51 - Antimony metalloid
Discovered by before 3000 BC in ~1600 BC
Antimony is a chemical element with symbol Sb (from Latin:stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were used for cosmetics; metallic antimony was also known, but it was erroneously identified as lead upon its discovery.
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 | 18 | 2 in 4s + 6 in 4p + 10 in 4d |
| 5 | 5 | 2 in 5s + 3 in 5p |
Electron shells
silvery lustrous gray Appearance
122 u Atomic Mass
1.45 Å Atomic Radius
1.86k K Boiling Point
15 Group
-3, 3, 5 Common Oxidation States
1.39 Å Covalent Radius
6.7 g/cm³ Density
101 kJ/mol Electron Affinity
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p3 Electron Configuration
[Kr] 4d10 5s2 5p3 Electron Configuration (semantic)
2.05 Electronegativity
51 Electrons
8.61 eV First Ionization Energy
-3, -2, -1, 3, 5 ICSD Oxidation States
834, 1594.9, 2440, 4260, 5400, 10400 kJ/mol Ionization Energies
904 K Melting Point
88 Mendeleev Number
25.2 J/(mol·K) Molar Heat
5 Number of Shells
5 Electron Valency
71 Neutrons
51 Atomic Number
29 Number of Isotopes
-3, 3, 5 Oxidation States
5 Period
Solid Phase
51 Protons
2, 8, 18, 18, 5 Electron Shell Occupations
0.207 J/(g K) Specific Heat