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Rb Rubidium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

37
Rb
Rubidium
Element 37 of Periodic table is Rubidium with atomic number 37, atomic weight 85.4678. Rubidium, symbol Rb, has a Body Centered Cubic structure and Silver color. Rubidium is a Alkali Metal element. It is part of group 1 (lithium family). Know everything about Rubidium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
37 Rb - Rubidium | SchoolMyKids

Rubidium is a chemical element with symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metallic element of the Alkali Metal group, with an atomic mass of 85.4678. Elemental rubidium is highly reactive, with properties similar to those of other alkali metals, such as very rapid oxidation in air.

It belongs to group 1 of the periodic table having trivial name alkali metals*. Hydrogen resides within this column, but is not considered an alkali metal.

Rubidium Facts

Read key information and facts about element Rubidium

NameRubidium
Atomic Number37
Atomic SymbolRb
Atomic Weight85.4678
PhaseSolid
ColorSilver
Appearancegrey white
ClassificationAlkali Metal
Group in Periodic Table1
Group Namelithium family
Period in Periodic Tableperiod 5
Block in Periodic Tables -block
Electronic Configuration[Kr] 5s1
Electronic Shell Structure (Electrons per shell)2, 8, 18, 8, 1
Melting Point312.46 K
Boiling Point961 K
CAS NumberCAS7440-17-7
Neighborhood Elements
123456789101112131415161718
1
1
H
Hydrogen
1.008

Atomic #

Electronic Shell #

Symbol
Name
Atomic Weight
HGas
HgLiquid
CSolid
Metals
Metalloids
NonMetals
Alkali metals
Alkali earth metals
Lanthanoids
Transition metals
Post-transition metals
Other nonmetals
Halogens
Nobel gas
Actinoids
2
He
Helium
4.003
2
3
Li
Lithium
6.941
4
Be
Beryllium
9.012
5
B
Boron
10.811
6
C
Carbon
12.011
7
N
Nitrogen
14.007
8
O
Oxygen
15.999
9
F
Fluorine
18.998
10
Ne
Neon
20.180
3
11
Na
Sodium
22.990
12
Mg
Magnesium
24.305
13
Al
Aluminium
26.982
14
Si
Silicon
28.085
15
P
Phosphorus
30.974
16
S
Sulfur
32.065
17
Cl
Chlorine
35.453
18
Ar
Argon
39.948
4
19
K
Potassium
39.098
20
Ca
Calcium
40.078
21
Sc
Scandium
44.956
22
Ti
Titanium
47.867
23
V
Vanadium
50.941
24
Cr
Chromium
51.996
25
Mn
Manganese
54.938
26
Fe
Iron
55.845
27
Co
Cobalt
58.933
28
Ni
Nickel
58.693
29
Cu
Copper
63.546
30
Zn
Zinc
65.409
31
Ga
Gallium
69.723
32
Ge
Germanium
72.640
33
As
Arsenic
74.922
34
Se
Selenium
78.960
35
Br
Bromine
79.904
36
Kr
Krypton
83.798
5
37
Rb
Rubidium
85.468
38
Sr
Strontium
87.620
39
Y
Yttrium
88.906
40
Zr
Zirconium
91.224
41
Nb
Niobium
92.906
42
Mo
Molybdenum
95.940
43
Tc
Technetium
98
44
Ru
Ruthenium
101.070
45
Rh
Rhodium
102.906
46
Pd
Palladium
106.420
47
Ag
Silver
107.868
48
Cd
Cadmium
112.411
49
In
Indium
114.818
50
Sn
Tin
118.710
51
Sb
Antimony
121.760
52
Te
Tellurium
127.600
53
I
Iodine
126.904
54
Xe
Xenon
131.293
6
55
Cs
Cesium
132.905
56
Ba
Barium
137.327
57 - 71
La - Lu
Lanthanides
72
Hf
Hafnium
178.490
73
Ta
Tantalum
180.948
74
W
Tungsten
183.840
75
Re
Rhenium
186.207
76
Os
Osmium
190.230
77
Ir
Iridium
192.217
78
Pt
Platinum
195.078
79
Au
Gold
196.967
80
Hg
Mercury
200.590
81
Tl
Thallium
204.383
82
Pb
Lead
207.200
83
Bi
Bismuth
208.980
84
Po
Polonium
209
85
At
Astatine
210
86
Rn
Radon
222
7
87
Fr
Francium
223
88
Ra
Radium
226
89 - 103
Ac - Lr
Actinides
104
Rf
Rutherfordium
261
105
Db
Dubnium
262
106
Sg
Seaborgium
266
107
Bh
Bohrium
264
108
Hs
Hassium
277
109
Mt
Meitnerium
268
110
Ds
Darmstadtium
281
111
Rg
Roentgenium
272
112
Cn
Copernicium
285
113
Nh
Nihonium
284
114
Fl
Flerovium
289
115
Mc
Moscovium
288
116
Lv
Livermorium
292
117
Ts
Tennessine
294
118
Og
Oganesson
294
Lanthanides
57
La
Lanthanum
138.905
58
Ce
Cerium
140.116
59
Pr
Praseodymium
140.908
60
Nd
Neodymium
144.240
61
Pm
Promethium
145
62
Sm
Samarium
150.360
63
Eu
Europium
151.964
64
Gd
Gadolinium
157.250
65
Tb
Terbium
158.925
66
Dy
Dysprosium
162.500
67
Ho
Holmium
164.930
68
Er
Erbium
167.259
69
Tm
Thulium
168.934
70
Yb
Ytterbium
173.040
71
Lu
Lutetium
174.967
Actinides
89
Ac
Actinium
227
90
Th
Thorium
232.038
91
Pa
Protactinium
231.036
92
U
Uranium
238.029
93
Np
Neptunium
237
94
Pu
Plutonium
244
95
Am
Americium
243
96
Cm
Curium
247
97
Bk
Berkelium
247
98
Cf
Californium
251
99
Es
Einsteinium
252
100
Fm
Fermium
257
101
Md
Mendelevium
258
102
No
Nobelium
259
103
Lr
Lawrencium
262

How to Locate Rubidium on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 37 to find Rubidium on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Rubidium on periodic table look for cross section of group 1 and period 5 in the modern periodic table.

Rubidium History

The element Rubidium was discovered by R. Bunsen and G. R. Kirchhoff in year 1861 in Germany. Rubidium was first isolated by Hevesy in . Rubidium derived its name from the Latin rubidus, meaning 'deep red'.

Bunsen and Kirchhoff discovered it just a few months after caesium, by observing new spectral lines in the minerallepidolite. Bunsen never obtained a pure sample of the metal, which was later obtained by Hevesy.

Rubidium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Rubidium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

 ppb by weight (1ppb =10^-7 %)ppb by atoms (1ppb =10^-7 %)
Abundance in Universe100.1
Abundance in Sun300.4
Abundance in Meteorites3300770
Abundance in Earth's Crust6000014000
Abundance in Oceans1208.7
Abundance in Humans4600340

Crystal Structure of Rubidium

The solid state structure of Rubidium is Body Centered Cubic.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

abc
558.5 pm558.5 pm558.5 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alphabetagamma
π/2 π/2 π/2

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group NameIm_ 3m 37 Rb Rubidium - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number229
Crystal StructureBody Centered Cubic

Rubidium Atomic and Orbital Properties

Rubidium atoms have 37 electrons and the electronic shell structure is [2, 8, 18, 8, 1] with Atomic Term Symbol (Quantum Numbers) 2S1/2.

Atomic Number37
Number of Electrons (with no charge)37
Number of Protons37
Mass Number85
Number of Neutrons48
Shell structure (Electrons per energy level)2, 8, 18, 8, 1
Electron Configuration[Kr] 5s1
Valence Electrons5s1
Valence (Valency)1
Main Oxidation States1
Oxidation States-1, 1
Atomic Term Symbol (Quantum Numbers)2S1/2

Bohr Atomic Model of Rubidium - Electrons per energy level

37 Rb Rubidium - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Rubidium - neutral Rubidium atom

Abbreviated electronic configuration of Rubidium

The ground state abbreviated electronic configuration of Neutral Rubidium atom is [Kr] 5s1. The portion of Rubidium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Kr]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 5s1, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Rubidium

Complete ground state electronic configuration for the Rubidium atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s1

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

  • As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
  • The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
  • Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
  • Electron configuration of Rubidium
    Atomic Structure of Rubidium

    Rubidium atomic radius is 265 pm, while it's covalent radius is 211 pm.

    Atomic Radius Calculated

    265 pm (2.65 Å)

    Atomic Radius Empirical

    235 pm (2.35 Å)

    Atomic Volume55.788 cm3/mol
    Covalent Radius211 pm (2.11 Å)
    Van der Waals Radius303 pm
    Neutron Cross Section0.38
    Neutron Mass Absorption 0.0003

    Atomic Spectrum of Rubidium

    Atomic Spectrum of Rubidium | SchoolMyKids

    Rubidium Chemical Properties: Rubidium Ionization Energies and electron affinity

    The electron affinity of Rubidium is 46.9 kJ/mol.

    Valence1
    Electronegativity0.82
    ElectronAffinity46.9 kJ/mol

    Ionization Energy of Rubidium

    Refer to table below for Ionization energies of Rubidium

    Ionization energy numberEnthalpy - kJ/mol
    1st403
    2nd2633
    3rd3860
    4th5080
    5th6850
    6th8140
    7th9570
    8th13120
    9th14500
    10th26740

    Rubidium Physical Properties

    Refer to below table for Rubidium Physical Properties

    Density1.532 g/cm3(when liquid at m.p density is $1.46 g/cm3)
    Molar Volume55.788 cm3/mol

    Elastic Properties

    Young Modulus2.4
    Shear Modulus-
    Bulk Modulus 2.5 GPa
    Poisson Ratio-

    Hardness of Rubidium - Tests to Measure of Hardness of Element

    Mohs Hardness0.3 MPa
    Vickers Hardness-
    Brinell Hardness0.216 MPa

    Rubidium Electrical Properties

    Rubidium is Conductor of electricity. Refer to table below for the Electrical properties ofRubidium

    Electrical Conductivity8300000 S/m
    Resistivity1.2e-7 m Ω
    Superconducting Point-

    Rubidium Heat and Conduction Properties

    Thermal Conductivity58 W/(m K)
    Thermal Expansion-

    Rubidium Magnetic Properties

    Magnetic TypeParamagnetic
    Curie Point-
    Mass Magnetic Susceptibility2.6e-9 m3/kg
    Molar Magnetic Susceptibility2.22e-10 m3/mol
    Volume Magnetic Susceptibility0.00000398

    Optical Properties of Rubidium

    Refractive Index-

    Acoustic Properties of Rubidium

    Speed of Sound1300 m/s

    Rubidium Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Rubidium

    Melting Point312.46 K (39.31°C, 102.75800000000001 °F)
    Boiling Point961 K (687.85°C, 1270.13 °F)
    Critical Temperature2093 K
    Superconducting Point-

    Enthalpies of Rubidium

    Heat of Fusion2.19 kJ/mol
    Heat of Vaporization72 kJ/mol
    Heat of Combustion-

    Rubidium Isotopes - Nuclear Properties of Rubidium

    Rubidium has 32 isotopes, with between 71 and 102 nucleons. Rubidium has 1 stable naturally occuring isotopes.

    Isotopes of Rubidium - Naturally occurring stable Isotopes: 85Rb.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    71Rb373471Synthetic
    72Rb373572Synthetic
    73Rb373673Synthetic
    74Rb373774Synthetic
    75Rb373875Synthetic
    76Rb373976Synthetic
    77Rb374077Synthetic
    78Rb374178Synthetic
    79Rb374279Synthetic
    80Rb374380Synthetic
    81Rb374481Synthetic
    82Rb374582Synthetic
    83Rb374683Synthetic
    84Rb374784Synthetic
    85Rb37488572.17%Stable
    86Rb374986Synthetic
    87Rb37508727.83%StableN/A
    88Rb375188Synthetic
    89Rb375289Synthetic
    90Rb375390Synthetic
    91Rb375491Synthetic
    92Rb375592Synthetic
    93Rb375693Synthetic
    94Rb375794Synthetic
    95Rb375895Synthetic
    96Rb375996Synthetic
    97Rb376097Synthetic
    98Rb376198Synthetic
    99Rb376299Synthetic
    100Rb3763100Synthetic
    101Rb3764101Synthetic
    102Rb3765102Synthetic