Rubidium 37

Atomic No. Order:

Alphabetic Order:

Periodic Table

2, 8, 18,

8, 1

H
1

Li
3

Na
11

K
19

Rb
37

Cs
55

Fr
87

Uue
119

Uhe
169

Bue
219

Rubidium

Symbol

Atomic Number

Relative Atomic Mass
¹²C = 12.0000

85.4678 (±3) [Since 1969]

Atomic Radius pm

247.5

First Ionisation Energy
kJ mol ^-1

403.0

Ionisation Energy (eV)

4.1771

Electronegativity

0.82

Density
kg m ^-3

1532 [293 K]
1475 [l., m.p.]

Molar Volume cm ³

55.79

Thermal Conductivity
W m ^-1 K ^-1

58.2 [300 K]

Melting Point K

312.2

Boiling Point K

961

Number of Isotopes

Isotope Atomic mass/u Mole fraction

85Rb 84.911 7924(27) 0.7217(2)
87Rb 86.909 1858(28) 0.2783(2)

Inner + outer Shells

Inner + outer Orbitals

Filling Orbital

5s ¹

Ground State Electron
Configuration

[Kr]

5s ¹

Ground State Electron
Configuration with
free Orbitals (n=17)

0, 0, 0, 10, 7

Ground State Electron
Configuration with
compressed Orbitals (n=56)

0, 0, 0, 14, 42

Singularity

110

	s		p	d	f	g	h	i	j
1	2
2	2		6
3	2		6	10
4	2		6	10	14
5	1	1	6	10	14	18
6
7
8

Term Symbol

²S _1/2

Discovery

It was discovered in the mineral lepidolite by the German chemist Robert Wilhelm Bunsen (University of Heidelberg, Germany) and the German physicist Gustav-Robert Kirchoff in 1861. Bunsen isolated rubidium in 1863.

Name Derived From

The name derives from the Latin rubidus for deepest red because of the two "deep red lines" in its spectra.

APSIDIUM ©	Created:		2002-06-04		037.pdf
	Page update:		2004-06-20		037.pdf