Chromium (symbol Cr, atomic number 24) is the metal that gives stainless steel its shine and corrosion resistance. It is classified as a transition metal and sits in group 6, period 4 of the periodic table.
Overview
Chromium is the chemical element with atomic number 24 and the symbol Cr. With a standard atomic weight of 51.996, it is a transition metal. In the periodic table it occupies group 6 and period 4, and under standard conditions it is normally a solid. Chromium is the metal that gives stainless steel its shine and corrosion resistance.
Atomic structure
An atom of Chromium has 24 protons in its nucleus and, when neutral, 24 electrons arranged in the configuration [Ar] 3d5 4s1. Its standard atomic weight of 51.996 reflects the natural mix of its stable isotopes.
Discovery and place in the table
Chromium was discovered in 1797 by Louis Nicolas Vauquelin. It follows Vanadium (V) and precedes Manganese (Mn) in order of atomic number.
| Atomic number | 24 |
|---|---|
| Symbol | Cr |
| Atomic mass | 51.996 |
| Category | Transition metal |
| Group | 6 |
| Period | 4 |
| Electron configuration | [Ar] 3d5 4s1 |
| Phase at STP | Solid |
| Discovered | 1797 (Louis Nicolas Vauquelin) |