TΦ Tables Physico-Chimiques

Iridium (Ir, Z = 77)

77 Ir 192,217 u

Métal de transition Bloc d Groupe 9 Période 6 Solide (CNTP)

Iridium is a chemical element with symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is generally credited with being the second densest element (after osmium) based on measured density, although calculations involving the space lattices of the elements show that iridium is denser. It is also the most corrosion-resistant metal, even at temperatures as high as 2000 °C. Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable.

Découvreur : Smithson Tennant

Propriétés physiques

Masse atomique standard
192,2 u
Densité
22,56 g/cm³
Point de fusion
2 719,0 K
Point d'ébullition
4 403,0 K
Chaleur molaire
25,10 J·mol⁻¹·K⁻¹
Électronégativité (Pauling)
2,200
Affinité électronique
150,9 kJ/mol
Énergies d'ionisation
880 ; 1 600 kJ/mol
Configuration électronique
[Xe] 4f14 5d7 6s2
Électrons par couche
K : 2 · L : 8 · M : 18 · N : 32 · O : 15 · P : 2
Aspect
silvery white

Correspondance ANU historique / conjectural

Comptage de la Chimie Occulte (1908) : 3 458 ANU (atomes ultimes), soit N/18 = 192,11 — masse « noologique » à comparer à la masse standard 192,217 u et à l'isotope dominant 193Ir. Coefficient k(Z) = 0,905

Matériel historique et conjectural — voir la page Pont ANU ↔ Nucléides.

Isotopes (43)

NucléideANMasse (u) Abondance (%)Demi-vieSpinParitéMagique
163Ir 163 86 162,994299 — stable 1/2 ⁺ —
164Ir 164 87 163,991966 — — 2 ⁻ —
165Ir 165 88 164,987552 — — 1/2 ⁺ —
166Ir 166 89 165,985716 — 10.5 ms 2 —
167Ir 167 90 166,981672 — 29.3 ms 1/2 ⁺ —
168Ir 168 91 167,979961 — 230 ms 2 —
169Ir 169 92 168,976282 — 353 ms 1/2 ⁺ —
170Ir 170 93 169,975113 — 910 ms 3 ⁻ —
171Ir 171 94 170,971646 — 3.1 s 1/2 ⁺ —
172Ir 172 95 171,970607 — 4.4 s 3 ⁻ —
173Ir 173 96 172,967505 — 9 s 1/2 ⁺ —
174Ir 174 97 173,966950 — 7.9 s 2 ⁺ —
175Ir 175 98 174,964150 — 9 s 1/2 ⁺ —
176Ir 176 99 175,963626 — 8.7 s 3 ⁺ —
177Ir 177 100 176,961301 — 29.8 s 5/2 ⁻ —
178Ir 178 101 177,961079 — 12 s 3 ⁺ —
179Ir 179 102 178,959118 — 79 s 5/2 —
180Ir 180 103 179,959229 — 1.5 min 5 ⁺ —
181Ir 181 104 180,957635 — 4.9 min 5/2 ⁻ —
182Ir 182 105 181,958076 — 15 min 3 ⁺ —
183Ir 183 106 182,956841 — 58 min 5/2 ⁻ —
184Ir 184 107 183,957476 — 3.09 h 5 ⁻ —
185Ir 185 108 184,956698 — 14.4 h 5/2 ⁻ —
186Ir 186 109 185,957947 — 16.64 h 5 ⁺ —
187Ir 187 110 186,957542 — 10.5 h 3/2 ⁺ —
188Ir 188 111 187,958835 — 41.5 h 1 —
189Ir 189 112 188,958723 — 13.2 j 3/2 ⁺ —
190Ir 190 113 189,960543 — 11.78 j 4 —
191Ir 191 114 190,960591 37,3000 stable 3/2 ⁺ —
192Ir 192 115 191,962602 — 73.82 j 4 ⁻ —
193Ir 193 116 192,962924 62,7000 stable 3/2 ⁺ —
194Ir 194 117 193,965076 — 19.35 h 1 ⁻ —
195Ir 195 118 194,965977 — 2.29 h 3/2 ⁺ —
196Ir 196 119 195,968400 — 52 s 1 —
197Ir 197 120 196,969657 — 5.8 min 3/2 ⁺ —
198Ir 198 121 197,972399 — 8.7 s 1 ⁻ —
199Ir 199 122 198,973807 — 7 s 3/2 ⁺ —
200Ir 200 123 199,976844 — 43 s 2 ⁻ —
201Ir 201 124 200,978701 — 21 s 3/2 ⁺ —
202Ir 202 125 201,982136 — 11 s 2 ⁻ —
203Ir 203 126 202,984573 — — 3/2 ⁺ N magique
204Ir 204 127 203,989726 — — — —
205Ir 205 128 204,993988 — — 3/2 ⁺ —

Liseré coloré en première colonne : vert = stable, jaune = demi-vie > 1 an, orange > 1 jour, rouge < 1 jour.