24Cr51.996
Chromium
Transition Metal
Solid at STP
Period 4Group 6Block DDiscovered 1797
[Ar]3d5 4s1
Chromium is a chemical element with symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard and brittle metal which takes a high polish, resists tarnishing, and has a high melting point.
📖 Read more on Wikipedia →Atomic Properties
| Atomic Number | 24 |
| Atomic Mass | 51.996 u |
| Electron Configuration | [Ar]3d5 4s1 |
| Oxidation States | +6, +3, +2 |
| Electronegativity | 1.66 (Pauling) |
| Atomic Radius | 189 pm |
| Ionization Energy | 6.767 eV |
| Electron Affinity | 0.666 eV |
| Block | D |
Physical Properties
| Appearance | silvery metallic |
| Standard State | Solid |
| Melting Point | 2180 K (1906.8 °C) |
| Boiling Point | 2944 K (2670.8 °C) |
| Density | 7.15 g/cm³ |
| Molar Heat | 23.35 J/(mol·K) |
| CPK Color | #8A99C7 |
Classification
| Category | Transition Metal |
| Group Block | Transition metal |
| Period | 4 |
| Group | 6 |
| Block | D |
Discovery
| Year Discovered | 1797 |
| Discovered By | Louis Nicolas Vauquelin |
| Electron Shells | 2, 8, 13, 1 |