Symbol
Mg
  
Rb
  
Period Number
3
  
5
  
Block
s block
  
s block
  
Element Family
Alkaline Earth
  
Alkali
  
Space Group Name
P63/mmc
  
Im_ 3m
  
Interesting Facts
- Magnesium ions are present in every chlorophyll of every green plant .
- Controlling Magnesium fire by pouring water on it will result in explosions.
  
- Rubidium metal is 16th most common element found in the earth crust.
- Rubidium metal also found in minerals as well as seawater.
  
Sources
By Electrolysis Process, In Ocean, Mining
  
Obtained from Lithium Production.
  
History
  
  
Who Discovered
Joseph Black
  
Robert Bunsen and Gustav Kirchhoff
  
Discovery
In 1755
  
In 1861
  
Abundance
  
  
Abundance In Sun
~0.000003 %
  
17
Abundance In Earth's Crust
Uses & Benefits
- Magnesium aluminum alloy improves the mechanical strength and welding characteristics and hence it is used in aeroplane and car manufacturing.
-
It is also used to remove sulfur from the molten iron and steel.
  
- 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.
  
Industrial Uses
Aerospace Industry, Ammunition Industry, Automobile Industry, Chemical Industry, Pharmaceutical Industry
  
NA
  
Medical Uses
NA
  
NA
  
Other Uses
Surgical Instruments Manufacturing
  
Alloys, Research Purposes
  
Biological Properties
  
  
Toxicity
Non Toxic
  
Non Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
37.80 Blood/mg dm-3
  
5
2.49 Blood/mg dm-3
  
7
In Bone
1,800.00 p.p.m.
  
4
5.00 p.p.m.
  
13
Boiling Point
1,107.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Grayish White
  
Luster
NA
  
NA
  
Hardness
  
  
Speed of Sound
4,940.00 m/s
  
11
1,300.00 m/s
  
99+
Optical Properties
  
  
Reflectivity
Not Available
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Mg
  
Rb
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
737.70 kJ/mol
  
24
403.00 kJ/mol
  
99+
2nd Energy Level
1,450.70 kJ/mol
  
99+
2,633.00 kJ/mol
  
6
3rd Energy Level
7,732.70 kJ/mol
  
5
3,860.00 kJ/mol
  
11
4th Energy Level
10,542.50 kJ/mol
  
4
5,080.00 kJ/mol
  
18
5th Energy Level
13,630.00 kJ/mol
  
3
6,850.00 kJ/mol
  
19
6th Energy Level
18,020.00 kJ/mol
  
3
8,140.00 kJ/mol
  
20
7th Energy level
21,711.00 kJ/mol
  
3
9,570.00 kJ/mol
  
20
8th Energy Level
25,661.00 kJ/mol
  
3
13,120.00 kJ/mol
  
17
9th Energy Level
31,653.00 kJ/mol
  
3
14,500.00 kJ/mol
  
18
10th Energy Level
35,458.00 kJ/mol
  
5
26,740.00 kJ/mol
  
6
11th Energy Level
169,988.00 kJ/mol
  
1
Not Available
  
12th Energy Level
189,368.00 kJ/mol
  
1
Not Available
  
Electrochemical Equivalent
0.45 g/amp-hr
  
99+
3.19 g/amp-hr
  
14
Other Chemical Properties
Corrosion, Highly Inflammable, Ionization, Solubility
  
Corrosion, Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Ne] 3s2
  
[Kr] 5s1
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
HCP-Crystal-Structure-of-Magnesium.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
13.97 cm3/mol
  
37
55.90 cm3/mol
  
2
Adjacent Atomic Numbers
  
  
Valence Electron Potential
40.00 (-eV)
  
99+
9.47 (-eV)
  
99+
Lattice Angles
π/2, π/2, 2 π/3
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
1.74 g/cm3
  
99+
1.53 g/cm3
  
99+
Density When Liquid (at m.p.)
1.58 g/cm3
  
99+
1.46 g/cm3
  
99+
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
NA
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
43.90 nΩ·m
  
99+
128.00 nΩ·m
  
26
Electrical Conductivity
0.23 106/cm Ω
  
7
0.08 106/cm Ω
  
24
Electron Affinity
0.00 kJ/mol
  
40
46.90 kJ/mol
  
24
Specific Heat
1.02 J/(kg K)
  
4
0.36 J/(kg K)
  
17
Molar Heat Capacity
24.87 J/mol·K
  
99+
31.06 J/mol·K
  
5
Thermal Conductivity
156.00 W/m·K
  
8
58.20 W/m·K
  
26
Critical Temperature
Not Available
  
Thermal Expansion
24.80 µm/(m·K)
  
15
90.00 µm/(m·K)
  
2
Enthalpy
  
  
Enthalpy of Vaporization
128.70 kJ/mol
  
99+
69.20 kJ/mol
  
99+
Enthalpy of Fusion
8.95 kJ/mol
  
39
2.19 kJ/mol
  
99+
Enthalpy of Atomization
148.50 kJ/mol
  
99+
82.00 kJ/mol
  
99+
Standard Molar Entropy
32.70 J/mol.K
  
99+
76.80 J/mol.K
  
5