Sodium Chromium Comparison
Periodic Table
Symbol
Na
Cr
Group Number
1
17
6
12
Period Number
3
4
Block
s block
d block
Element Family
Alkali
Transition Metal
CAS Number
7440235
99+
7440473
39
Space Group Name
Im_ 3m
Im_ 3m
Space Group Number
229.00
1
229.00
1
Facts
Interesting Facts
- 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).
- Chromium is highly reactive, hence it is not found free in nature.
- Ores of Chromites mineral are the major source of Chromium metal.
- Almost 90% leather tanning is done with the help of chromium.
Sources
By Electrolysis Process, Mining
Found in Minerals, Mining, Ores of metals, Ores of Minerals
History
Who Discovered
Humphry Davy
Louis Nicolas Vauquelin
Discovery
In 1807
In Between 1797 - 1798
Abundance
Abundance In Universe
2 * 10-3 %
6
1.5 * 10-3 %
7
Abundance In Sun
~0.004 %
6
~0.002 %
7
Abundance In Meteorites
0.55 %
6
0.30 %
7
Abundance In Earth's Crust
2.30 %
5
0.01 %
13
Abundance In Oceans
1.10 %
1
0.00 %
16
Abundance In Humans
0.14 %
3
0.00 %
16
Uses
Uses & Benefits
- In some nuclear reactors sodium is used as a heat exchanger.
- Compound of Sodium metals called Salt (Sodium chloride) is used in Food.
- It is used to harden the steel and produces a stainless steel and other various alloys.
- It is also used to give proper finish to polished mirrors. Its chromium plates are used in bathroom fittings.
Industrial Uses
Electrical Industry, Electronic Industry
Automobile Industry, Chemical Industry
Medical Uses
Pharmaceutical Industry
NA
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Toxic
Highly Toxic
Present in Human Body
Yes
Yes
In Blood
1,970.00 Blood/mg dm-3
1
0.11 Blood/mg dm-3
12
In Bone
10,000.00 p.p.m.
2
0.33 p.p.m.
21
Physical Properties
Melting Point
97.72 °C
99+
1,857.00 °C
14
Boiling Point
883.00 °C
99+
2,672.00 °C
39
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silver
Luster
Metallic
Metallic
Hardness
Mohs Hardness
0.50
22
8.50
1
Brinell Hardness
0.69 MPa
99+
687.00 MPa
16
Vickers Hardness
Not Available
1,060.00 MPa
10
Speed of Sound
3,200.00 m/s
24
5,940.00 m/s
5
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
Na
Cr
Isotopes
Known Isotopes
17
22
21
18
Electronegativity
Pauling Electronegativity
0.93
99+
1.66
18
Sanderson Electronegativity
0.56
30
1.66
14
Allred Rochow Electronegativity
1.01
35
1.56
10
Mulliken-Jaffe Electronegativity
0.91
21
Not Available
Allen Electronegativity
0.87
99+
1.65
19
Electropositivity
Pauling Electropositivity
3.07
6
2.34
36
Ionization Energies
1st Energy Level
495.80 kJ/mol
99+
26,130.00 kJ/mol
1
2nd Energy Level
4,562.00 kJ/mol
4
28,750.00 kJ/mol
1
3rd Energy Level
6,910.30 kJ/mol
6
34,230.00 kJ/mol
1
4th Energy Level
9,543.00 kJ/mol
5
37,066.00 kJ/mol
1
5th Energy Level
13,354.00 kJ/mol
4
97,510.00 kJ/mol
1
6th Energy Level
16,613.00 kJ/mol
4
105,800.00 kJ/mol
1
7th Energy level
20,117.00 kJ/mol
4
114,300.00 kJ/mol
1
8th Energy Level
25,496.00 kJ/mol
4
125,300.00 kJ/mol
1
9th Energy Level
28,932.00 kJ/mol
4
134,700.00 kJ/mol
1
10th Energy Level
141,362.00 kJ/mol
2
144,300.00 kJ/mol
1
11th Energy Level
159,076.00 kJ/mol
2
26,130.00 kJ/mol
12
12th Energy Level
Not Available
28,750.00 kJ/mol
13
13th Energy Level
Not Available
34,230.00 kJ/mol
10
14th Energy Level
Not Available
37,066.00 kJ/mol
12
15th Energy Level
Not Available
97,510.00 kJ/mol
1
16th Energy Level
Not Available
105,800.00 kJ/mol
2
17th Energy Level
Not Available
114,300.00 kJ/mol
3
18th Energy Level
Not Available
125,300.00 kJ/mol
4
19th Energy Level
Not Available
134,700.00 kJ/mol
5
20th Energy Level
Not Available
144,300.00 kJ/mol
7
21st Energy Level
Not Available
157,700.00 kJ/mol
7
22nd Energy Level
Not Available
166,090.00 kJ/mol
6
Electrochemical Equivalent
0.86 g/amp-hr
99+
0.32 g/amp-hr
99+
Electron Work Function
2.75 eV
40
4.50 eV
14
Other Chemical Properties
Chemical Stability, Corrosion, Flammability, Ionization, Solubility
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
11
99+
24
99+
Electron Configuration
[Ne] 3s1
[Ar] 3d5 4s1
Crystal Structure
Body Centered Cubic (BCC)
Body Centered Cubic (BCC)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
11
99+
24
99+
Number of Neutrons
12
99+
28
99+
Number of Electrons
11
99+
24
99+
Radius of an Atom
Atomic Radius
186.00 pm
9
128.00 pm
99+
Covalent Radius
166.00 pm
27
139.00 pm
99+
Van der Waals Radius
227.00 pm
21
200.00 pm
28
Atomic Weight
22.99 amu
99+
52.00 amu
99+
Atomic Volume
23.70 cm3/mol
10
7.23 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
14.10 (-eV)
99+
170.00 (-eV)
4
Lattice Constant
429.06 pm
19
291.00 pm
99+
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
0.97 g/cm3
99+
7.19 g/cm3
99+
Density When Liquid (at m.p.)
0.93 g/cm3
99+
6.30 g/cm3
40
Tensile Strength
Not Available
689.00 MPa
7
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
Not Available
0.00 (Pa)
24
Vapor Pressure at 2000 K
Not Available
774.00 (Pa)
1
Elasticity properties
Shear Modulus
3.30 GPa
99+
115.00 GPa
9
Bulk Modulus
6.30 GPa
99+
160.00 GPa
11
Young's Modulus
10.00 GPa
99+
279.00 GPa
8
Poisson Ratio
Not Available
0.21
32
Other Mechanical Properties
NA
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
0.97
99+
7.19
99+
Magnetic Ordering
Paramagnetic
Antiferromagnetic
Electrical Properties
Electrical Property
Conductor
NA
Resistivity
47.70 nΩ·m
99+
125.00 nΩ·m
27
Electrical Conductivity
0.21 106/cm Ω
9
0.08 106/cm Ω
25
Electron Affinity
52.80 kJ/mol
19
64.30 kJ/mol
15
Thermal Properties
Specific Heat
1.23 J/(kg K)
3
0.45 J/(kg K)
12
Molar Heat Capacity
28.23 J/mol·K
10
23.35 J/mol·K
99+
Thermal Conductivity
142.00 W/m·K
11
93.90 W/m·K
17
Critical Temperature
2,573.00 K
2
Not Available
Thermal Expansion
71.00 µm/(m·K)
4
4.90 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
89.04 kJ/mol
99+
348.80 kJ/mol
24
Enthalpy of Fusion
2.59 kJ/mol
99+
15.31 kJ/mol
20
Enthalpy of Atomization
108.40 kJ/mol
99+
397.50 kJ/mol
21
Standard Molar Entropy
51.30 J/mol.K
28
23.80 J/mol.K
99+
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