| Name | iridium |
|---|---|
| Symbol | Ir |
| Atomic Weight | 192.217 |
| Atomic Number | 77 |
| CAS ID | 7439-88-5 |
| Group Number | 9 |
| Group Name | Precious Metal |
| Period Number | 6 |
| Origin of Name | Latin, Iris = "rainbow." |
| Year Discovered | 1803 |
| Discovery Credits | Discovered by S. Tennant at London, UK. |
| Class | Metallic |
| Color | Silvery White |
| Standard State | Solid at 77 F & 298 K |
| Description | Hard, lustrous, silvery metal of the platinum group. Stable
to air and water, inert to all acids, but fused NaOH will attack it. Used
in special alloys and spark plugs. Diagnostic tests: |