प्वलाख

प्वलाख वा Platinum छता रसायनिक तत्त्व ख। थ्व तत्त्वया रसायनिक चिं Pt ख। थ्व तत्त्वया एतमिक ल्या ७८ ख।

प्वलाख
78Pt
Pd ↑ Pt ↓ Ds Periodic table इरिडियम ← प्वलाख → लुं
रुप
grayish white
साधारण गुण
नां, चिं, ल्या	प्वलाख, Pt, 78
उच्चारण	/ˈplætɨnəm/
धातुया वर्ग	transition metal
ग्रुप, पिरियद, ब्लक	10, 6, d
Standard atomic weight	195.084
Electron configuration	[Xe] 4f14 5d9 6s1 2, 8, 18, 32, 17, 1
History
Discovery	Antonio de Ulloa (1735)
First isolation	Antonio de Ulloa (1735)
Physical properties
Phase	solid
Density (near r.t.)	21.45 g·cm−3
Liquid density at m.p.	19.77 g·cm−3
Melting point	2041.4 K, 1768.3 °C, 3214.9 °F
Boiling point	4098 K, 3825 °C, 6917 °F
Heat of fusion	22.17 kJ·mol−1
Heat of vaporization	510 kJ·mol−1
Molar heat capacity	25.86 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2330 (2550) 2815 3143 3556 4094
Atomic properties
Oxidation states	6, 5, 4, 3, 2, 1, −1, −2 (mildly basic oxide)
Electronegativity	2.28 (Pauling scale)
Ionization energies	1st: 870 kJ·mol−1
	2nd: 1791 kJ·mol−1
Atomic radius	139 pm
Covalent radius	136±5 pm
Van der Waals radius	175 pm
Miscellanea
Crystal structure	face-centered cubic
Magnetic ordering	paramagnetic
Electrical resistivity	(20 °C) 105 nΩ·m
Thermal conductivity	71.6 W·m−1·K−1
Thermal expansion	(25 °C) 8.8 µm·m−1·K−1
Speed of sound (thin rod)	(r.t.) 2800 m·s−1
Tensile strength	125-240 MPa
Young's modulus	168 GPa
Shear modulus	61 GPa
Bulk modulus	230 GPa
Poisson ratio	0.38
Mohs hardness	4–4.5
Vickers hardness	549 MPa
Brinell hardness	392 MPa
CAS registry number	7440-06-4
Most stable isotopes
iso NA half-life DM DE (MeV) DP 190Pt 0.014% 6.5×1011 y α 3.252 186Os 192Pt 0.782% >4.7×1016 y (α) 2.4181 188Os 193Pt syn 50 y ε - 193Ir 194Pt 32.967% - (α) 1.5045 190Os 195Pt 33.832% - (α) 1.1581 191Os 196Pt 25.242% - (α) 0.7942 192Os 198Pt 7.163% >3.2×1014 y (α) 0.0870 194Os (β−β−) 1.0472 198Hg Decay modes in parentheses are predicted, but have not yet been observed