Rhodium, 45Rh
 |
| General properties |
| Name, seembol |
rhodium, Rh |
| Appearance |
silvery white metallic |
| Pronunciation |
ROH-dee-əm |
| Rhodium in the periodic cairt |
|
|
| Atomic nummer (Z) |
45 |
| Group, block |
group 9, d-block |
| Period |
period 5 |
| Element category |
transeetion metal |
| Staundart atomic wicht (Ar) |
102.90550 |
| Electron configuration |
[Kr] 5s1 4d8 |
|
per shell
|
2, 8, 18, 16, 1 |
| Pheesical properties |
| Phase |
solid |
| Meltin pynt |
2237 K (1964 °C, 3567 °F) |
| Bylin pynt |
3968 K (3695 °C, 6683 °F) |
| Density near r.t. |
12.41 g/cm3 |
| when liquid, at m.p. |
10.7 g/cm3 |
| Heat o fusion |
26.59 kJ/mol |
| Heat o vapourisation |
494 kJ/mol |
| Molar heat capacity |
24.98 J/(mol·K) |
vapour pressur
| P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
| at T (K) |
2288 |
2496 |
2749 |
3063 |
3405 |
3997 |
|
| Atomic properties |
| Oxidation states |
6, 5, 4, 3, 2, 1[1], -1
(amphoteric oxide) |
| Electronegativity |
Pauling scale: 2.28 |
| Atomic radius |
empirical: 134 pm |
| Covalent radius |
142±7 pm |
| Miscellanea |
| Crystal structur |
face-centered cubic (fcc)
|
| Speed o soond thin rod |
4700 m/s (at 20 °C) |
| Thermal expansion |
8.2 µm/(m·K) (at 25 °C) |
| Thermal conductivity |
150 W/(m·K) |
| Electrical resistivity |
43.3 n Ω·m (at 0 °C) |
| Magnetic orderin |
paramagnetic[2] |
| Young's modulus |
380 GPa |
| Shear modulus |
150 GPa |
| Bulk modulus |
275 GPa |
| Poisson ratio |
0.26 |
| Mohs haurdness |
6.0 |
| Vickers haurdness |
1246 MPa |
| Brinell haurdness |
1100 MPa |
| CAS Nummer |
7440-16-6 |
| History |
| Discovery |
William Hyde Wollaston (1804) |
| First isolation |
William Hyde Wollaston (1804) |
| Maist stable isotopes o rhodium |
| iso |
NA |
hauf-life |
DM |
DE (MeV) |
DP |
| 99Rh |
syn |
16.1 d |
ε |
- |
99Ru |
| γ |
0.089, 0.353,
0.528 |
- |
| 101mRh |
syn |
4.34 d |
ε |
- |
101Ru |
| IT |
0.157 |
101Rh |
| γ |
0.306, 0.545 |
- |
| 101Rh |
syn |
3.3 y |
ε |
- |
101Ru |
| γ |
0.127, 0.198,
0.325 |
- |
| 102mRh |
syn |
2.9 y |
ε |
- |
102Ru |
| γ |
0.475, 0.631,
0.697, 1.046 |
- |
| 102Rh |
syn |
207 d |
ε |
- |
102Ru |
| β+ |
0.826, 1.301 |
102Ru |
| β− |
1.151 |
102Pd |
| γ |
0.475, 0.628 |
- |
| 103Rh |
100% |
- |
(SF) |
<15.462 |
|
| 105Rh |
syn |
35.36 h |
β− |
0.247, 0.260,
0.566 |
105Pd |
| γ |
0.306, 0.318 |
- |
|
| Decay modes in parentheses are predictit, but hae nae yet been observed |
|
· references |
Rhodium is a chemical element that is a rare, sillery-white, haird, an chemically inert transeetion metal an a member o the platinum group. It haes the chemical seembol Rh an atomic nummer 45. It is componed o anly ane naiturally-occurrin isotope, 103Rh. Naiturally occurrin rhodium is uisually foond as the free metal, alloyed wi seemilar metals, an rarely as a chemical compoond in minerals such as bowieite an rhodplumsite. It is ane o the rarest an maist valuable precious metals.
