Rubidium vs Calcium
Periodic Table
Symbol
Rb
Ca
Group Number
1
17
2
16
Period Number
5
4
Block
s block
s block
Element Family
Alkali
Alkaline Earth
CAS Number
7440177
99+
7440702
21
Space Group Name
Im_ 3m
Fm_ 3m
Space Group Number
229.00
1
225.00
2
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.
- Calcium ranks 5th rank in the list of earth’s abundance Percentage.
- It is found in the compound state.
- Gypsum or calcium sulfate is used as plaster and plaster of paris.
Sources
Obtained from Lithium Production.
Earth's crust, Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Robert Bunsen and Gustav Kirchhoff
Humphry Davy
Discovery
In 1861
In 1808
Abundance
Abundance In Universe
1 * 10-6 %
16
7 * 10-3 %
3
Abundance In Sun
~0.000003 %
17
~0.007 %
4
Abundance In Meteorites
0.00 %
19
1.10 %
4
Abundance In Earth's Crust
0.01 %
18
5.00 %
3
Abundance In Oceans
0.00 %
7
0.00 %
5
Abundance In Humans
0.00 %
7
1.40 %
1
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 used as a reducing agent while preparing metals like thorium and uranium. It is also used as an alloying agent for metals such as aluminum, copper & lead.
- Calcium carbonate or lime stone is used in cement.
Industrial Uses
NA
Chemical Industry
Medical Uses
NA
Dentistry, Pharmaceutical Industry
Other Uses
Alloys, Research Purposes
Alloys
Biological Properties
Toxicity
Non Toxic
Non Toxic
Present in Human Body
Yes
Yes
In Blood
2.49 Blood/mg dm-3
7
60.50 Blood/mg dm-3
4
In Bone
5.00 p.p.m.
13
170,000.00 p.p.m.
1
Physical Properties
Melting Point
38.89 °C
99+
839.00 °C
99+
Boiling Point
688.00 °C
99+
1,484.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Grayish White
Gray
Luster
NA
NA
Hardness
Mohs Hardness
0.30
24
1.75
17
Brinell Hardness
0.22 MPa
99+
170.00 MPa
99+
Speed of Sound
1,300.00 m/s
99+
3,810.00 m/s
19
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
Ca
Isotopes
Known Isotopes
29
10
19
20
Electronegativity
Pauling Electronegativity
0.82
99+
1.00
99+
Sanderson Electronegativity
0.31
32
0.95
24
Allred Rochow Electronegativity
0.89
40
1.04
34
Mulliken-Jaffe Electronegativity
0.69
24
1.08
17
Allen Electronegativity
0.71
99+
1.03
39
Electropositivity
Pauling Electropositivity
3.18
3
3.00
9
Ionization Energies
1st Energy Level
403.00 kJ/mol
99+
589.80 kJ/mol
99+
2nd Energy Level
2,633.00 kJ/mol
6
1,145.40 kJ/mol
99+
3rd Energy Level
3,860.00 kJ/mol
11
4,912.40 kJ/mol
7
4th Energy Level
5,080.00 kJ/mol
18
6,491.00 kJ/mol
7
5th Energy Level
6,850.00 kJ/mol
19
8,153.00 kJ/mol
7
6th Energy Level
8,140.00 kJ/mol
20
10,496.00 kJ/mol
8
7th Energy level
9,570.00 kJ/mol
20
12,270.00 kJ/mol
12
8th Energy Level
13,120.00 kJ/mol
17
14,206.00 kJ/mol
15
9th Energy Level
14,500.00 kJ/mol
18
18,191.00 kJ/mol
12
10th Energy Level
26,740.00 kJ/mol
6
20,385.00 kJ/mol
16
11th Energy Level
Not Available
57,110.00 kJ/mol
3
12th Energy Level
Not Available
63,410.00 kJ/mol
3
13th Energy Level
Not Available
70,110.00 kJ/mol
3
14th Energy Level
Not Available
78,890.00 kJ/mol
4
15th Energy Level
Not Available
86,310.00 kJ/mol
5
16th Energy Level
Not Available
94,000.00 kJ/mol
6
17th Energy Level
Not Available
104,900.00 kJ/mol
7
18th Energy Level
Not Available
111,711.00 kJ/mol
8
Electrochemical Equivalent
3.19 g/amp-hr
14
0.75 g/amp-hr
99+
Electron Work Function
2.16 eV
99+
2.87 eV
38
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
Chemical Stability, Flammability, Ionization, Solubility
Atomic Properties
Atomic Number
37
99+
20
99+
Electron Configuration
[Kr] 5s1
[Ar] 4s2
Crystal Structure
Body Centered Cubic (BCC)
Face Centered Cubic (FCC)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
FCC-Crystal-Structure-of-Calcium.jpg#100
Atom
Number of Protons
37
99+
20
99+
Number of Neutrons
48
99+
20
99+
Number of Electrons
37
99+
20
99+
Radius of an Atom
Atomic Radius
248.00 pm
2
197.00 pm
6
Covalent Radius
220.00 pm
4
176.00 pm
22
Van der Waals Radius
303.00 pm
3
231.00 pm
19
Atomic Weight
85.47 amu
99+
40.08 amu
99+
Atomic Volume
55.90 cm3/mol
2
29.90 cm3/mol
7
Adjacent Atomic Numbers
Valence Electron Potential
9.47 (-eV)
99+
29.00 (-eV)
99+
Lattice Constant
558.50 pm
10
558.84 pm
9
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+
1.55 g/cm3
99+
Density When Liquid (at m.p.)
1.46 g/cm3
99+
1.38 g/cm3
99+
Tensile Strength
Not Available
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
Not Available
25.50 (Pa)
3
Elasticity properties
Shear Modulus
Not Available
7.40 GPa
99+
Bulk Modulus
2.50 GPa
99+
17.00 GPa
99+
Young's Modulus
2.40 GPa
99+
20.00 GPa
99+
Poisson Ratio
Not Available
0.31
13
Other Mechanical Properties
Ductile
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
1.53
99+
4.58
99+
Magnetic Ordering
Paramagnetic
Diamagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
128.00 nΩ·m
26
33.60 nΩ·m
99+
Electrical Conductivity
0.08 106/cm Ω
24
0.30 106/cm Ω
6
Electron Affinity
46.90 kJ/mol
24
2.37 kJ/mol
39
Thermal Properties
Specific Heat
0.36 J/(kg K)
17
0.63 J/(kg K)
7
Molar Heat Capacity
31.06 J/mol·K
5
25.93 J/mol·K
34
Thermal Conductivity
58.20 W/m·K
26
201.00 W/m·K
5
Critical Temperature
2,093.00 K
4
Not Available
Thermal Expansion
90.00 µm/(m·K)
2
22.30 µm/(m·K)
19
Enthalpy
Enthalpy of Vaporization
69.20 kJ/mol
99+
150.00 kJ/mol
99+
Enthalpy of Fusion
2.19 kJ/mol
99+
8.54 kJ/mol
99+
Enthalpy of Atomization
82.00 kJ/mol
99+
184.00 kJ/mol
99+
Standard Molar Entropy
76.80 J/mol.K
5
41.60 J/mol.K
36
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