Symbol
K
  
Ca
  
Period Number
4
  
4
  
Block
s block
  
s block
  
Element Family
Alkali
  
Alkaline Earth
  
Space Group Name
Im_ 3m
  
Fm_ 3m
  
Interesting Facts
- In the list of most abundant element Potassium is ranked 7th.
- Potassium can easily be sliced (chopped) down using knife.
  
- 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
Found in Minerals, Mining
  
Earth's crust, Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Humphry Davy
  
Humphry Davy
  
Discovery
In 1807
  
In 1808
  
Abundance
  
  
Abundance In Earth's Crust
Uses & Benefits
- Potassium’s compounds are in high demand for their application in Fertilizer manufacturing.
- Potassium carbonate is used in glass manufacturing and Potassium carbonate in manufacturing detergent and body wash.
  
- 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
Ammunition Industry, Chemical Industry
  
Chemical Industry
  
Medical Uses
Pharmaceutical Industry
  
Dentistry, Pharmaceutical Industry
  
Other Uses
NA
  
Alloys
  
Biological Properties
  
  
Toxicity
Toxic
  
Non Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
1,620.00 Blood/mg dm-3
  
2
60.50 Blood/mg dm-3
  
4
In Bone
2,100.00 p.p.m.
  
3
170,000.00 p.p.m.
  
1
Boiling Point
1,484.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery Gray
  
Gray
  
Luster
NA
  
NA
  
Hardness
  
  
Brinell Hardness
170.00 MPa
  
99+
Speed of Sound
2,000.00 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 Formula
K
  
Ca
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
418.80 kJ/mol
  
99+
589.80 kJ/mol
  
99+
2nd Energy Level
3,052.00 kJ/mol
  
5
1,145.40 kJ/mol
  
99+
3rd Energy Level
4,420.00 kJ/mol
  
8
4,912.40 kJ/mol
  
7
4th Energy Level
5,877.00 kJ/mol
  
9
6,491.00 kJ/mol
  
7
5th Energy Level
7,975.00 kJ/mol
  
8
8,153.00 kJ/mol
  
7
6th Energy Level
9,590.00 kJ/mol
  
13
10,496.00 kJ/mol
  
8
7th Energy level
11,343.00 kJ/mol
  
17
12,270.00 kJ/mol
  
12
8th Energy Level
14,944.00 kJ/mol
  
13
14,206.00 kJ/mol
  
15
9th Energy Level
16,963.70 kJ/mol
  
15
18,191.00 kJ/mol
  
12
10th Energy Level
48,610.00 kJ/mol
  
3
20,385.00 kJ/mol
  
16
11th Energy Level
54,490.00 kJ/mol
  
4
57,110.00 kJ/mol
  
3
12th Energy Level
60,730.00 kJ/mol
  
4
63,410.00 kJ/mol
  
3
13th Energy Level
68,950.00 kJ/mol
  
4
70,110.00 kJ/mol
  
3
14th Energy Level
75,900.00 kJ/mol
  
5
78,890.00 kJ/mol
  
4
15th Energy Level
83,080.00 kJ/mol
  
6
86,310.00 kJ/mol
  
5
16th Energy Level
93,400.00 kJ/mol
  
7
94,000.00 kJ/mol
  
6
17th Energy Level
99,710.00 kJ/mol
  
8
104,900.00 kJ/mol
  
7
18th Energy Level
Not Available
  
111,711.00 kJ/mol
  
8
Electrochemical Equivalent
1.46 g/amp-hr
  
99+
0.75 g/amp-hr
  
99+
Other Chemical Properties
Chemical Stability, Flammability, Ionization, Solubility
  
Chemical Stability, Flammability, Ionization, Solubility
  
Electron Configuration
[Ar] 4s1
  
[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
  
  
Radius of an Atom
  
  
Atomic Volume
45.46 cm3/mol
  
3
29.90 cm3/mol
  
7
Adjacent Atomic Numbers
  
  
Valence Electron Potential
10.40 (-eV)
  
99+
29.00 (-eV)
  
99+
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
0.86 g/cm3
  
99+
1.55 g/cm3
  
99+
Density When Liquid (at m.p.)
0.83 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
  
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
NA
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Diamagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
33.60 nΩ·m
  
99+
Electrical Conductivity
0.14 106/cm Ω
  
14
0.30 106/cm Ω
  
6
Electron Affinity
48.40 kJ/mol
  
22
2.37 kJ/mol
  
39
Specific Heat
0.75 J/(kg K)
  
6
0.63 J/(kg K)
  
7
Molar Heat Capacity
29.60 J/mol·K
  
6
25.93 J/mol·K
  
34
Thermal Conductivity
102.50 W/m·K
  
15
201.00 W/m·K
  
5
Critical Temperature
Not Available
  
Thermal Expansion
83.30 µm/(m·K)
  
3
22.30 µm/(m·K)
  
19
Enthalpy
  
  
Enthalpy of Vaporization
77.50 kJ/mol
  
99+
150.00 kJ/mol
  
99+
Enthalpy of Fusion
2.32 kJ/mol
  
99+
8.54 kJ/mol
  
99+
Enthalpy of Atomization
89.50 kJ/mol
  
99+
184.00 kJ/mol
  
99+
Standard Molar Entropy
64.70 J/mol.K
  
18
41.60 J/mol.K
  
36