Symbol
Mg
  
Ca
  
Period Number
3
  
4
  
Block
s block
  
s block
  
Element Family
Alkaline Earth
  
Alkaline Earth
  
Space Group Name
P63/mmc
  
Fm_ 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.
  
- 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
By Electrolysis Process, In Ocean, Mining
  
Earth's crust, Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Joseph Black
  
Humphry Davy
  
Discovery
In 1755
  
In 1808
  
Abundance
  
  
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.
  
- 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
Aerospace Industry, Ammunition Industry, Automobile Industry, Chemical Industry, Pharmaceutical Industry
  
Chemical Industry
  
Medical Uses
NA
  
Dentistry, Pharmaceutical Industry
  
Other Uses
Surgical Instruments Manufacturing
  
Alloys
  
Biological Properties
  
  
Toxicity
Non Toxic
  
Non Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
37.80 Blood/mg dm-3
  
5
60.50 Blood/mg dm-3
  
4
In Bone
1,800.00 p.p.m.
  
4
170,000.00 p.p.m.
  
1
Boiling Point
1,107.00 °C
  
99+
1,484.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Gray
  
Gray
  
Luster
NA
  
NA
  
Hardness
  
  
Brinell Hardness
170.00 MPa
  
99+
Speed of Sound
4,940.00 m/s
  
11
3,810.00 m/s
  
19
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
  
Ca
  
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
589.80 kJ/mol
  
99+
2nd Energy Level
1,450.70 kJ/mol
  
99+
1,145.40 kJ/mol
  
99+
3rd Energy Level
7,732.70 kJ/mol
  
5
4,912.40 kJ/mol
  
7
4th Energy Level
10,542.50 kJ/mol
  
4
6,491.00 kJ/mol
  
7
5th Energy Level
13,630.00 kJ/mol
  
3
8,153.00 kJ/mol
  
7
6th Energy Level
18,020.00 kJ/mol
  
3
10,496.00 kJ/mol
  
8
7th Energy level
21,711.00 kJ/mol
  
3
12,270.00 kJ/mol
  
12
8th Energy Level
25,661.00 kJ/mol
  
3
14,206.00 kJ/mol
  
15
9th Energy Level
31,653.00 kJ/mol
  
3
18,191.00 kJ/mol
  
12
10th Energy Level
35,458.00 kJ/mol
  
5
20,385.00 kJ/mol
  
16
11th Energy Level
169,988.00 kJ/mol
  
1
57,110.00 kJ/mol
  
3
12th Energy Level
189,368.00 kJ/mol
  
1
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
0.45 g/amp-hr
  
99+
0.75 g/amp-hr
  
99+
Other Chemical Properties
Corrosion, Highly Inflammable, Ionization, Solubility
  
Chemical Stability, Flammability, Ionization, Solubility
  
Electron Configuration
[Ne] 3s2
  
[Ar] 4s2
  
Crystal Structure
Hexagonal Close Packed (HCP)
  
Face Centered Cubic (FCC)
  
Crystal Lattice
HCP-Crystal-Structure-of-Magnesium.jpg#100
  
FCC-Crystal-Structure-of-Calcium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
13.97 cm3/mol
  
37
29.90 cm3/mol
  
7
Adjacent Atomic Numbers
  
  
Valence Electron Potential
40.00 (-eV)
  
99+
29.00 (-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+
1.55 g/cm3
  
99+
Density When Liquid (at m.p.)
1.58 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
  
Elasticity properties
  
  
Other Mechanical Properties
NA
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Diamagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
43.90 nΩ·m
  
99+
33.60 nΩ·m
  
99+
Electrical Conductivity
0.23 106/cm Ω
  
7
0.30 106/cm Ω
  
6
Electron Affinity
0.00 kJ/mol
  
40
2.37 kJ/mol
  
39
Specific Heat
1.02 J/(kg K)
  
4
0.63 J/(kg K)
  
7
Molar Heat Capacity
24.87 J/mol·K
  
99+
25.93 J/mol·K
  
34
Thermal Conductivity
156.00 W/m·K
  
8
201.00 W/m·K
  
5
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
24.80 µm/(m·K)
  
15
22.30 µm/(m·K)
  
19
Enthalpy
  
  
Enthalpy of Vaporization
128.70 kJ/mol
  
99+
150.00 kJ/mol
  
99+
Enthalpy of Fusion
8.95 kJ/mol
  
39
8.54 kJ/mol
  
99+
Enthalpy of Atomization
148.50 kJ/mol
  
99+
184.00 kJ/mol
  
99+
Standard Molar Entropy
32.70 J/mol.K
  
99+
41.60 J/mol.K
  
36