77 2 · 8 · 18 · 32 · 15 · 2

Iridium, Ir, element 77

Transition metal· Period 6· Group 9· d-block

Configuration [Xe]4f¹⁴5d⁷6s²

Atomic weight: 192.217Da
Phase: solid
Density: 22.5622g/cm³
Melting point: 2,719.15K 2,446 °C
Boiling point: 4,701.15K 4,428 °C
Electronegativity: 2.2

Very hard and brittle, silvery metallic transition element. It has a yellowish cast to it. Salts of iridium are highly colored. It is the most corrosion resistant metal known, not attacked by any acid, but is attacked by molten salts. There are two natural isotopes of iridium, and 4 radioisotopes, the most stable being Ir-192 with a half-life of 73.83 days. Ir-192 decays into Platinum, while the other radioisotopes decay into Osmium. Iridium is used in high temperature apparatus, electrical contacts, and as a hardening agent for platinumpy. Discovered in 1803 by Smithson Tennant in England. The name comes from the Greek word iris, which means rainbow. Iridium metal is generally non-toxic due to its relative unreactivity, but iridium compounds should be considered highly toxic. Description from mendeleev.

Back to the table

The outermost shell: the valence electronsThe inner shellsThe nucleus One bead for each electron, on the ring of its shell, counted from the nucleus out. The rings turn at their own pace; the model is Bohr's picture of the atom, which places electrons in shells but not on true orbits.

Atomic properties

5 of 5 fields have a value for iridium

Atomic weight The standard atomic weight. For an element with no stable isotope, the mass of its longest-lived isotope.: 192.217Da; Source: mendeleev
Electron configuration: [Xe]4f¹⁴5d⁷6s²; Source: mendeleev
Uncertainty of the atomic weight: 0.003Da; Source: mendeleev
Electron configuration in full The electron configuration with the noble-gas core written out.: 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰4f¹⁴5s²5p⁶5d⁷6s²; Source: Worked outfrom electron configuration
Electrons in each shell Counted from the electron configuration, from the first shell outward.: 2 · 8 · 18 · 32 · 15 · 2; Source: Worked outfrom electron configuration

Screening of each subshell

Clementi's screening constants: how much of the nucleus's charge the other electrons hide from an electron in each subshell. What is left is the effective nuclear charge it feels.

Subshell	Screening σ	Effective charge Z − σ
1s	1.4881	75.5119
2s	20.1102	56.8898
2p	4.4624	72.5376
3s	22.7942	54.2058
3p	21.9311	55.0689
3d	13.514	63.486
4s	34.152	42.848
4p	35.086	41.914
4d	37.2628	39.7372
4f	38.6552	38.3448
5s	51.1545	25.8455
5p	53.339	23.661
5d	58.304	18.696
6s	66.4334	10.5666