Symbol
K
  
Na
  
Period Number
4
  
3
  
Block
s block
  
s block
  
Element Family
Alkali
  
Alkali
  
Space Group Name
Im_ 3m
  
Im_ 3m
  
Interesting Facts
- In the list of most abundant element Potassium is ranked 7th.
- Potassium can easily be sliced (chopped) down using knife.
  
- At room temperature Sodium metal is very soft as it can be chopped down into pieces with butter knife.
- The most common compound of Sodium is NaCl (Salt).
  
Sources
Found in Minerals, Mining
  
By Electrolysis Process, Mining
  
History
  
  
Who Discovered
Humphry Davy
  
Humphry Davy
  
Discovery
In 1807
  
In 1807
  
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.
  
- In some nuclear reactors sodium is used as a heat exchanger.
- Compound of Sodium metals called Salt (Sodium chloride) is used in Food.
  
Industrial Uses
Ammunition Industry, Chemical Industry
  
Electrical Industry, Electronic Industry
  
Medical Uses
Pharmaceutical Industry
  
Pharmaceutical Industry
  
Other Uses
NA
  
Alloys
  
Biological Properties
  
  
Toxicity
Toxic
  
Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
1,620.00 Blood/mg dm-3
  
2
1,970.00 Blood/mg dm-3
  
1
In Bone
2,100.00 p.p.m.
  
3
10,000.00 p.p.m.
  
2
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery Gray
  
Silvery White
  
Luster
NA
  
Metallic
  
Hardness
  
  
Speed of Sound
2,000.00 m/s
  
99+
3,200.00 m/s
  
24
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
  
Na
  
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+
495.80 kJ/mol
  
99+
2nd Energy Level
3,052.00 kJ/mol
  
5
4,562.00 kJ/mol
  
4
3rd Energy Level
4,420.00 kJ/mol
  
8
6,910.30 kJ/mol
  
6
4th Energy Level
5,877.00 kJ/mol
  
9
9,543.00 kJ/mol
  
5
5th Energy Level
7,975.00 kJ/mol
  
8
13,354.00 kJ/mol
  
4
6th Energy Level
9,590.00 kJ/mol
  
13
16,613.00 kJ/mol
  
4
7th Energy level
11,343.00 kJ/mol
  
17
20,117.00 kJ/mol
  
4
8th Energy Level
14,944.00 kJ/mol
  
13
25,496.00 kJ/mol
  
4
9th Energy Level
16,963.70 kJ/mol
  
15
28,932.00 kJ/mol
  
4
10th Energy Level
48,610.00 kJ/mol
  
3
141,362.00 kJ/mol
  
2
11th Energy Level
54,490.00 kJ/mol
  
4
159,076.00 kJ/mol
  
2
12th Energy Level
60,730.00 kJ/mol
  
4
Not Available
  
13th Energy Level
68,950.00 kJ/mol
  
4
Not Available
  
14th Energy Level
75,900.00 kJ/mol
  
5
Not Available
  
15th Energy Level
83,080.00 kJ/mol
  
6
Not Available
  
16th Energy Level
93,400.00 kJ/mol
  
7
Not Available
  
17th Energy Level
99,710.00 kJ/mol
  
8
Not Available
  
Electrochemical Equivalent
1.46 g/amp-hr
  
99+
0.86 g/amp-hr
  
99+
Other Chemical Properties
Chemical Stability, Flammability, Ionization, Solubility
  
Chemical Stability, Corrosion, Flammability, Ionization, Solubility
  
Electron Configuration
[Ar] 4s1
  
[Ne] 3s1
  
Crystal Structure
Body Centered Cubic (BCC)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
45.46 cm3/mol
  
3
23.70 cm3/mol
  
10
Adjacent Atomic Numbers
  
  
Valence Electron Potential
10.40 (-eV)
  
99+
14.10 (-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+
0.97 g/cm3
  
99+
Density When Liquid (at m.p.)
0.83 g/cm3
  
99+
0.93 g/cm3
  
99+
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Poisson Ratio
Not Available
  
Not Available
  
Other Mechanical Properties
NA
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
47.70 nΩ·m
  
99+
Electrical Conductivity
0.14 106/cm Ω
  
14
0.21 106/cm Ω
  
9
Electron Affinity
48.40 kJ/mol
  
22
52.80 kJ/mol
  
19
Specific Heat
0.75 J/(kg K)
  
6
1.23 J/(kg K)
  
3
Molar Heat Capacity
29.60 J/mol·K
  
6
28.23 J/mol·K
  
10
Thermal Conductivity
102.50 W/m·K
  
15
142.00 W/m·K
  
11
Thermal Expansion
83.30 µm/(m·K)
  
3
71.00 µm/(m·K)
  
4
Enthalpy
  
  
Enthalpy of Vaporization
77.50 kJ/mol
  
99+
89.04 kJ/mol
  
99+
Enthalpy of Fusion
2.32 kJ/mol
  
99+
2.59 kJ/mol
  
99+
Enthalpy of Atomization
89.50 kJ/mol
  
99+
108.40 kJ/mol
  
99+
Standard Molar Entropy
64.70 J/mol.K
  
18
51.30 J/mol.K
  
28