Nodyn:Infobox rubidium

kryptonrwbidiwmstrontium
K

Rb

Cs
Ymddangosiad
llwydwyn
Nodweddion cyffredinol
Enw, symbol, rhif rwbidiwm, Rb, 37
Ynganiad /r[invalid input: 'ʉ']ˈbɪdiəm/ roo-BID-ee-əm
Teulu'r elfennau alkali metal
Grŵp, cyfnod, bloc 15, s
Rhif atomig 85.4678(3)
Patrwm yr Electronnau [Kr] 5s1
Electronnau / cragen 2, 8, 18, 8, 1 (Image)
Nodweddion ffisegol
Stâd solid
Dwysedd (oddeutu tymheredd yr ystafell) 1.532 g·cm−3
Dwysedd hylif / Ymdoddbwynt 1.46 g·cm−3
Ymdoddbwynt 312.46 K, 39.31 °C, 102.76 °F
Berwbwynt 961 K, 688 °C, 1270 °F
Pwynt critigol (extrapolated) 2093 K, 16 MPa
Enthalpi ymdoddiad

Gwres o ymdoddi

kJ·mol−1
Enthalpi anweddiad Cynhwysedd gwres 31.060 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 434 486 552 641 769 958
Nodweddion Atomig
cyflwr ocsidiad 1
(strongly basic oxide)
Electronegativity 0.82 (Graddfa Pauling)
Ionization energies 1st: 403 kJ·mol−1
2: 2632.1 kJ·mol−1
3ydd: 3859.4 kJ·mol−1
Radiws atomig 248 pm
Radiws cofalent 220±9 pm
Radiws Van der Waals 303 pm
Amrywiol
Strwythyr y crisal body-centered cubic
Magnetic ordering paramagnetic[1]
Gwrthedd trydanol (20 °C) 128 nΩ·m
Dargludiad Thermal 58.2 W·m−1·K−1
Cyflymder sain (20 °C) 1300 m·s−1
Modwlws Young 2.4 GPa
Modwlws Bulk 2.5 GPa
Graddfa caledwch Mohs 0.3
Brinell hardness 0.216 MPa
CAS registry number 7440-17-7
Most stable isotopes
Main article: Isotopes of rwbidiwm
iso NA half-life DM DE (MeV) DP

Nodyn:Elementbox isotopes decay2 Nodyn:Elementbox isotopes decay4

85Rb 72.168% 85Rb is stable with 48 neutrons

Nodyn:Elementbox isotopes decay2

87Rb 27.835% 4.88 × 1010 y β 0.283 87Sr
· r

References

  1. Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.