Radium Strontium Comparison
Periodic Table
Symbol
Ra
Sr
Group Number
2
16
2
16
Period Number
7
5
Block
s block
s block
Element Family
Alkaline Earth
Alkaline Earth
CAS Number
7440144
99+
7440246
99+
Space Group Name
Im_ 3m
Fm_ 3m
Space Group Number
229.00
1
225.00
2
Facts
Interesting Facts
- Radium metal is the heaviest metal of Alkaline earth metals column.
- Radium metal is highly radioactive and does not have any stable isotopes.
- Strontium element is softer than Calcium.
- Silvery Strontium turns yellow, if exposed to air.
Sources
Mining, Ores of metals
Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Not Available
William Cruickshank
Discovery
In 1898
In 1787
Abundance
Abundance In Universe
Not Available
4 * 10-6 %
14
Abundance In Sun
~-9999 %
~0.000005 %
15
Abundance In Meteorites
Not Available
0.00 %
15
Abundance In Earth's Crust
0.00 %
99+
0.04 %
10
Abundance In Oceans
0.00 %
99+
0.00 %
4
Abundance In Humans
0.00 %
20
0.00 %
7
Uses
Uses & Benefits
- It is a highly radioactive metal; and sometime Radium-223 is used to treat prostate cancer.
- It is used in luminous paints.
- Strontium metal is used to producing ferrite magnets as well as refining zinc.
- By-product of nuclear reactors called Strontium-90 is a radioactive isotope; it is absorbed by tissues and destroys bone marrow and cancer growth.
Industrial Uses
NA
Ammunition Industry, Chemical Industry
Medical Uses
Pharmaceutical Industry
NA
Other Uses
NA
Alloys
Biological Properties
Toxicity
Highly Toxic
Non Toxic
Present in Human Body
No
Yes
In Blood
Not Available
0.03 Blood/mg dm-3
19
In Bone
Not Available
140.00 p.p.m.
7
Physical Properties
Melting Point
700.00 °C
99+
769.00 °C
99+
Boiling Point
1,737.00 °C
99+
1,384.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery White
Luster
Metallic
Metallic
Hardness
Mohs Hardness
Not Available
1.50
18
Speed of Sound
Not Available
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
Ra
Sr
Isotopes
Known Isotopes
33
6
27
12
Electronegativity
Pauling Electronegativity
0.90
99+
0.95
99+
Sanderson Electronegativity
Not Available
0.72
27
Allred Rochow Electronegativity
0.97
38
0.99
37
Mulliken-Jaffe Electronegativity
0.92
20
1.00
18
Allen Electronegativity
0.89
99+
0.96
40
Electropositivity
Pauling Electropositivity
3.10
5
3.05
7
Ionization Energies
1st Energy Level
509.30 kJ/mol
99+
549.50 kJ/mol
99+
2nd Energy Level
979.00 kJ/mol
99+
1,064.20 kJ/mol
99+
3rd Energy Level
Not Available
4,138.00 kJ/mol
10
4th Energy Level
Not Available
5,500.00 kJ/mol
13
5th Energy Level
Not Available
6,910.00 kJ/mol
18
6th Energy Level
Not Available
8,760.00 kJ/mol
18
7th Energy level
Not Available
10,230.00 kJ/mol
19
8th Energy Level
Not Available
11,800.00 kJ/mol
19
9th Energy Level
Not Available
15,600.00 kJ/mol
17
10th Energy Level
Not Available
17,100.00 kJ/mol
19
11th Energy Level
Not Available
31,270.00 kJ/mol
6
Electrochemical Equivalent
4.22 g/amp-hr
6
1.64 g/amp-hr
99+
Electron Work Function
Not Available
2.59 eV
99+
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Atomic Properties
Atomic Number
88
30
38
99+
Electron Configuration
[Rn] 7s2
[Kr] 5s2
Crystal Structure
Body Centered Cubic (BCC)
Face Centered Cubic (FCC)
Crystal Lattice
BCC-Crystal-Structure-.jpg#100
FCC-Crystal-Structure-of-Strontium.jpg#100
Atom
Number of Protons
88
30
38
99+
Number of Neutrons
138
16
50
99+
Number of Electrons
88
30
38
99+
Radius of an Atom
Atomic Radius
Not Available
215.00 pm
5
Covalent Radius
221.00 pm
3
195.00 pm
15
Van der Waals Radius
283.00 pm
4
249.00 pm
7
Atomic Weight
226.00 amu
26
87.62 amu
99+
Atomic Volume
45.20 cm3/mol
4
33.70 cm3/mol
6
Adjacent Atomic Numbers
Valence Electron Potential
20.10 (-eV)
99+
25.70 (-eV)
99+
Lattice Constant
514.80 pm
13
608.49 pm
6
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
5.50 g/cm3
99+
2.64 g/cm3
99+
Density When Liquid (at m.p.)
Not Available
2.38 g/cm3
99+
Tensile Strength
Not Available
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
Not Available
121.00 (Pa)
1
Elasticity properties
Shear Modulus
Not Available
6.03 GPa
99+
Young's Modulus
Not Available
15.70 GPa
99+
Poisson Ratio
Not Available
0.28
17
Other Mechanical Properties
NA
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
5.00
99+
2.64
99+
Magnetic Ordering
Nonmagnetic
Paramagnetic
Electrical Properties
Electrical Property
NA
NA
Resistivity
100.00 nΩ·m
31
132.00 nΩ·m
24
Electrical Conductivity
Not Available
0.08 106/cm Ω
26
Electron Affinity
Not Available
5.03 kJ/mol
38
Thermal Properties
Specific Heat
0.12 J/(kg K)
40
0.30 J/(kg K)
18
Molar Heat Capacity
Not Available
26.40 J/mol·K
28
Thermal Conductivity
18.60 W/m·K
99+
35.40 W/m·K
37
Critical Temperature
Not Available
Not Available
Thermal Expansion
Not Available
22.50 µm/(m·K)
18
Enthalpy
Enthalpy of Vaporization
Not Available
150.00 kJ/mol
99+
Enthalpy of Fusion
Not Available
9.16 kJ/mol
38
Enthalpy of Atomization
163.00 kJ/mol
99+
163.20 kJ/mol
99+
Standard Molar Entropy
71.00 J/mol.K
14
55.00 J/mol.K
26
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