Chromium vs Radium
Periodic Table
Symbol
Cr
Ra
Group Number
6
12
2
16
Period Number
4
7
Block
d block
s block
Element Family
Transition Metal
Alkaline Earth
CAS Number
7440473
39
7440144
99+
Space Group Name
Im_ 3m
Im_ 3m
Space Group Number
229.00
1
229.00
1
Facts
Interesting Facts
- 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.
- Radium metal is the heaviest metal of Alkaline earth metals column.
- Radium metal is highly radioactive and does not have any stable isotopes.
Sources
Found in Minerals, Mining, Ores of metals, Ores of Minerals
Mining, Ores of metals
History
Who Discovered
Louis Nicolas Vauquelin
Not Available
Discovery
In Between 1797 - 1798
In 1898
Abundance
Abundance In Universe
1.5 * 10-3 %
7
Not Available
Abundance In Sun
~0.002 %
7
~-9999 %
Abundance In Meteorites
0.30 %
7
Not Available
Abundance In Earth's Crust
0.01 %
13
0.00 %
99+
Abundance In Oceans
0.00 %
16
0.00 %
99+
Abundance In Humans
0.00 %
16
0.00 %
20
Uses
Uses & Benefits
- 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.
- It is a highly radioactive metal; and sometime Radium-223 is used to treat prostate cancer.
- It is used in luminous paints.
Industrial Uses
Automobile Industry, Chemical Industry
NA
Medical Uses
NA
Pharmaceutical Industry
Other Uses
Alloys
NA
Biological Properties
Toxicity
Highly Toxic
Highly Toxic
Present in Human Body
Yes
No
In Blood
0.11 Blood/mg dm-3
12
Not Available
In Bone
0.33 p.p.m.
21
Not Available
Physical Properties
Melting Point
1,857.00 °C
14
700.00 °C
99+
Boiling Point
2,672.00 °C
39
1,737.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silver
Silvery White
Luster
Metallic
Metallic
Hardness
Mohs Hardness
8.50
1
Not Available
Brinell Hardness
687.00 MPa
16
Not Available
Vickers Hardness
1,060.00 MPa
10
Not Available
Speed of Sound
5,940.00 m/s
5
Not Available
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
Cr
Ra
Isotopes
Known Isotopes
21
18
33
6
Electronegativity
Pauling Electronegativity
1.66
18
0.90
99+
Sanderson Electronegativity
1.66
14
Not Available
Allred Rochow Electronegativity
1.56
10
0.97
38
Mulliken-Jaffe Electronegativity
Not Available
0.92
20
Allen Electronegativity
1.65
19
0.89
99+
Electropositivity
Pauling Electropositivity
2.34
36
3.10
5
Ionization Energies
1st Energy Level
26,130.00 kJ/mol
1
509.30 kJ/mol
99+
2nd Energy Level
28,750.00 kJ/mol
1
979.00 kJ/mol
99+
3rd Energy Level
34,230.00 kJ/mol
1
Not Available
4th Energy Level
37,066.00 kJ/mol
1
Not Available
5th Energy Level
97,510.00 kJ/mol
1
Not Available
6th Energy Level
105,800.00 kJ/mol
1
Not Available
7th Energy level
114,300.00 kJ/mol
1
Not Available
8th Energy Level
125,300.00 kJ/mol
1
Not Available
9th Energy Level
134,700.00 kJ/mol
1
Not Available
10th Energy Level
144,300.00 kJ/mol
1
Not Available
11th Energy Level
26,130.00 kJ/mol
12
Not Available
12th Energy Level
28,750.00 kJ/mol
13
Not Available
13th Energy Level
34,230.00 kJ/mol
10
Not Available
14th Energy Level
37,066.00 kJ/mol
12
Not Available
15th Energy Level
97,510.00 kJ/mol
1
Not Available
16th Energy Level
105,800.00 kJ/mol
2
Not Available
17th Energy Level
114,300.00 kJ/mol
3
Not Available
18th Energy Level
125,300.00 kJ/mol
4
Not Available
19th Energy Level
134,700.00 kJ/mol
5
Not Available
20th Energy Level
144,300.00 kJ/mol
7
Not Available
21st Energy Level
157,700.00 kJ/mol
7
Not Available
22nd Energy Level
166,090.00 kJ/mol
6
Not Available
Electrochemical Equivalent
0.32 g/amp-hr
99+
4.22 g/amp-hr
6
Electron Work Function
4.50 eV
14
Not Available
Other Chemical Properties
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Ionization, Radioactive Isotopes, Radioactivity
Atomic Properties
Atomic Number
24
99+
88
30
Electron Configuration
[Ar] 3d5 4s1
[Rn] 7s2
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
24
99+
88
30
Number of Neutrons
28
99+
138
16
Number of Electrons
24
99+
88
30
Radius of an Atom
Atomic Radius
128.00 pm
99+
Not Available
Covalent Radius
139.00 pm
99+
221.00 pm
3
Van der Waals Radius
200.00 pm
28
283.00 pm
4
Atomic Weight
52.00 amu
99+
226.00 amu
26
Atomic Volume
7.23 cm3/mol
99+
45.20 cm3/mol
4
Adjacent Atomic Numbers
Valence Electron Potential
170.00 (-eV)
4
20.10 (-eV)
99+
Lattice Constant
291.00 pm
99+
514.80 pm
13
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
7.19 g/cm3
99+
5.50 g/cm3
99+
Density When Liquid (at m.p.)
6.30 g/cm3
40
Not Available
Tensile Strength
689.00 MPa
7
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)
24
Not Available
Vapor Pressure at 2000 K
774.00 (Pa)
1
Not Available
Elasticity properties
Shear Modulus
115.00 GPa
9
Not Available
Bulk Modulus
160.00 GPa
11
Not Available
Young's Modulus
279.00 GPa
8
Not Available
Poisson Ratio
0.21
32
Not Available
Other Mechanical Properties
NA
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
7.19
99+
5.00
99+
Magnetic Ordering
Antiferromagnetic
Nonmagnetic
Electrical Properties
Electrical Property
NA
NA
Resistivity
125.00 nΩ·m
27
100.00 nΩ·m
31
Electrical Conductivity
0.08 106/cm Ω
25
Not Available
Electron Affinity
64.30 kJ/mol
15
Not Available
Thermal Properties
Specific Heat
0.45 J/(kg K)
12
0.12 J/(kg K)
40
Molar Heat Capacity
23.35 J/mol·K
99+
Not Available
Thermal Conductivity
93.90 W/m·K
17
18.60 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
4.90 µm/(m·K)
99+
Not Available
Enthalpy
Enthalpy of Vaporization
348.80 kJ/mol
24
Not Available
Enthalpy of Fusion
15.31 kJ/mol
20
Not Available
Enthalpy of Atomization
397.50 kJ/mol
21
163.00 kJ/mol
99+
Standard Molar Entropy
23.80 J/mol.K
99+
71.00 J/mol.K
14
|
||
|
||
|
