Rubidium Barium Comparison
Periodic Table
Symbol
Rb
Ba
Group Number
1
17
2
16
Period Number
5
6
Block
s block
s block
Element Family
Alkali
Alkaline Earth
CAS Number
7440177
99+
7440393
99+
Space Group Name
Im_ 3m
Im_ 3m
Space Group Number
229.00
1
229.00
1
Facts
Interesting Facts
- Rubidium metal is 16th most common element found in the earth crust.
- Rubidium metal also found in minerals as well as seawater.
- Barium oxidizes very easily in the air.
- All toxic compounds of Barium can easily dissolve in water.
- Barium carbonate is used to produce a Rat poison and its other compound Barium nitrate is used in fireworks to produce green color.
Sources
Obtained from Lithium Production.
Earth's crust, Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Robert Bunsen and Gustav Kirchhoff
Carl Wilhelm Scheele
Discovery
In 1861
In 1772
Abundance
Abundance In Universe
1 * 10-6 %
16
1 * 10-6 %
16
Abundance In Sun
~0.000003 %
17
~0.000001 %
18
Abundance In Meteorites
0.00 %
19
0.00 %
20
Abundance In Earth's Crust
0.01 %
18
0.03 %
11
Abundance In Oceans
0.00 %
7
0.00 %
8
Abundance In Humans
0.00 %
7
0.00 %
12
Uses
Uses & Benefits
- Rubidium's main application is in the glass manufacturing.
- Rubidium can very easily get ionized and hence it is used for ion engines, but it is still less efficient than that of Caesium.
- It is sued in chemical paint manufacturing and glass manufacturing.
- Compounds of this metal are toxic; but still the barium sulfate is insoluble and given to patients suffering from digestive disorder.
Industrial Uses
NA
Ammunition Industry, Automobile Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
NA
Other Uses
Alloys, Research Purposes
Alloys
Biological Properties
Toxicity
Non Toxic
Low Toxic
Present in Human Body
Yes
Yes
In Blood
2.49 Blood/mg dm-3
7
0.07 Blood/mg dm-3
15
In Bone
5.00 p.p.m.
13
70.00 p.p.m.
9
Physical Properties
Melting Point
38.89 °C
99+
725.00 °C
99+
Boiling Point
688.00 °C
99+
1,140.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Grayish White
Silvery Gray
Luster
NA
NA
Hardness
Mohs Hardness
0.30
24
1.25
19
Brinell Hardness
0.22 MPa
99+
Not Available
Speed of Sound
1,300.00 m/s
99+
1,620.00 m/s
99+
Optical Properties
Allotropes
No
No
α Allotropes
Not Available
Not Available
β Allotropes
Not Available
Not Available
γ Allotropes
Not Available
Not Available
Chemical Properties
Chemical Formula
Rb
Ba
Isotopes
Known Isotopes
29
10
37
2
Electronegativity
Pauling Electronegativity
0.82
99+
0.89
99+
Sanderson Electronegativity
0.31
32
0.68
28
Allred Rochow Electronegativity
0.89
40
0.97
38
Mulliken-Jaffe Electronegativity
0.69
24
0.88
22
Allen Electronegativity
0.71
99+
0.88
99+
Electropositivity
Pauling Electropositivity
3.18
3
3.11
4
Ionization Energies
1st Energy Level
403.00 kJ/mol
99+
502.90 kJ/mol
99+
2nd Energy Level
2,633.00 kJ/mol
6
965.20 kJ/mol
99+
3rd Energy Level
3,860.00 kJ/mol
11
3,600.00 kJ/mol
14
4th Energy Level
5,080.00 kJ/mol
18
Not Available
5th Energy Level
6,850.00 kJ/mol
19
Not Available
6th Energy Level
8,140.00 kJ/mol
20
Not Available
7th Energy level
9,570.00 kJ/mol
20
Not Available
8th Energy Level
13,120.00 kJ/mol
17
Not Available
9th Energy Level
14,500.00 kJ/mol
18
Not Available
10th Energy Level
26,740.00 kJ/mol
6
Not Available
Electrochemical Equivalent
3.19 g/amp-hr
14
2.56 g/amp-hr
20
Electron Work Function
2.16 eV
99+
2.70 eV
99+
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Atomic Properties
Atomic Number
37
99+
56
99+
Electron Configuration
[Kr] 5s1
[Xe] 6s2
Crystal Structure
Body Centered Cubic (BCC)
Body Centered Cubic (BCC)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
37
99+
56
99+
Number of Neutrons
48
99+
81
99+
Number of Electrons
37
99+
56
99+
Radius of an Atom
Atomic Radius
248.00 pm
2
222.00 pm
4
Covalent Radius
220.00 pm
4
215.00 pm
5
Van der Waals Radius
303.00 pm
3
268.00 pm
6
Atomic Weight
85.47 amu
99+
137.33 amu
99+
Atomic Volume
55.90 cm3/mol
2
39.24 cm3/mol
5
Adjacent Atomic Numbers
Valence Electron Potential
9.47 (-eV)
99+
21.30 (-eV)
99+
Lattice Constant
558.50 pm
10
502.80 pm
15
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
1.53 g/cm3
99+
3.51 g/cm3
99+
Density When Liquid (at m.p.)
1.46 g/cm3
99+
3.34 g/cm3
99+
Tensile Strength
Not Available
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
Not Available
7.11 (Pa)
6
Elasticity properties
Shear Modulus
Not Available
4.90 GPa
99+
Bulk Modulus
2.50 GPa
99+
9.60 GPa
99+
Young's Modulus
2.40 GPa
99+
13.00 GPa
99+
Poisson Ratio
Not Available
Not Available
Other Mechanical Properties
Ductile
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
1.53
99+
3.62
99+
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Superconductor
Resistivity
128.00 nΩ·m
26
332.00 nΩ·m
13
Electrical Conductivity
0.08 106/cm Ω
24
0.03 106/cm Ω
40
Electron Affinity
46.90 kJ/mol
24
13.95 kJ/mol
36
Thermal Properties
Specific Heat
0.36 J/(kg K)
17
0.20 J/(kg K)
30
Molar Heat Capacity
31.06 J/mol·K
5
28.07 J/mol·K
12
Thermal Conductivity
58.20 W/m·K
26
18.40 W/m·K
99+
Critical Temperature
2,093.00 K
4
Not Available
Thermal Expansion
90.00 µm/(m·K)
2
20.60 µm/(m·K)
22
Enthalpy
Enthalpy of Vaporization
69.20 kJ/mol
99+
140.00 kJ/mol
99+
Enthalpy of Fusion
2.19 kJ/mol
99+
7.66 kJ/mol
99+
Enthalpy of Atomization
82.00 kJ/mol
99+
175.70 kJ/mol
99+
Standard Molar Entropy
76.80 J/mol.K
5
62.50 J/mol.K
20
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