Symbol
Sr
Po
Group Number
216
0
17
👆🏻
Period Number
56
2
7
👆🏻
Block
s block
p block
Element Family
Alkaline Earth
Post-Transition
CAS Number
74402467440086
7429905
54386242
👆🏻
Space Group Name
Fm_ 3m
Pm-3m
Space Group Number
225.00221.00
11
276
👆🏻
Interesting Facts
- Strontium element is softer than Calcium.
- Silvery Strontium turns yellow, if exposed to air.
- Polonium was the first radioactive element to be discovered.
- Polonium element and its compounds are highly radioactive.
- Its alloy with Beryllium provides source of neutrons.
Sources
Found in Minerals, Mining, Ores of Minerals
Mining, Ores of metals
History
Who Discovered
William Cruickshank
Pierre Curie and Marie Curie
Discovery
In 1787
In 1898
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %-
0
0.1
👆🏻
Abundance In Meteorites
0.00 %-
0
22
👆🏻
Abundance In Earth's Crust
0.04 %0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
0.00 %0.00 %
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- 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.
- Polonium metal has different Allotropes, it is used in antistatic devices and for research purpose.
- A 1 gram of Polonium can reach a temperature of 500°C, hence it is used as a heat source for space equipment.
Industrial Uses
Ammunition Industry, Chemical Industry
Aerospace Industry, Ammunition Industry
Medical Uses
-
-
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Non Toxic
Highly Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.03 Blood/mg dm-30.00 Blood/mg dm-3
0
1970
👆🏻
In Bone
140.00 p.p.m.0.00 p.p.m.
0
170000
👆🏻
Melting Point
769.00 °C254.00 °C
-38.83
3410
👆🏻
Boiling Point
1,384.00 °C962.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silver
Luster
Metallic
-
Hardness
Mohs Hardness
1.502.50
0.2
8.5
👆🏻
Brinell Hardness
110.00 MPa70.00 MPa
0.14
3490
👆🏻
Vickers Hardness
15.00 MPa30.00 MPa
0
3920
👆🏻
Speed of Sound
4,170.00 m/s2,260.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.432.70
0.155
3.41
👆🏻
Reflectivity
65.00 %50.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
α-polonium
β Allotropes
-
β-polonium
γ Allotropes
-
-
Chemical Formula
Sr
Po
Isotopes
Known Isotopes
2729
0
38
👆🏻
Electronegativity
Pauling Electronegativity
0.952.00
0
2.6
👆🏻
Sanderson Electronegativity
0.722.00
0.22
2.56
👆🏻
Allred Rochow Electronegativity
0.991.76
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.002.48
0.62
2.48
👆🏻
Allen Electronegativity
0.962.19
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
3.052.00
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
549.50 kJ/mol812.10 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,064.20 kJ/mol1,833.20 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
4,138.00 kJ/mol812.10 kJ/mol
392.8
34230
👆🏻
4th Energy Level
5,500.00 kJ/mol8,121.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
6,910.00 kJ/mol8,120.00 kJ/mol
392
97510
👆🏻
6th Energy Level
8,760.00 kJ/mol8,120.00 kJ/mol
1007
105800
👆🏻
7th Energy level
10,230.00 kJ/mol8,120.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
11,800.00 kJ/mol8,120.00 kJ/mol
730
125300
👆🏻
9th Energy Level
15,600.00 kJ/mol8,120.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
17,100.00 kJ/mol8,120.00 kJ/mol
392
144300
👆🏻
11th Energy Level
31,270.00 kJ/mol8,120.00 kJ/mol
392
169988
👆🏻
12th Energy Level
5,490.00 kJ/mol8,120.00 kJ/mol
0
189368
👆🏻
13th Energy Level
5,490.00 kJ/mol8,120.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
5,490.00 kJ/mol8,120.00 kJ/mol
380
86450
👆🏻
15th Energy Level
54,900.00 kJ/mol81,200.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
54,900.00 kJ/mol81,200.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
549.50 kJ/mol812.10 kJ/mol
375.7
122200
👆🏻
18th Energy Level
5,490.00 kJ/mol8,120.00 kJ/mol
0
134810
👆🏻
19th Energy Level
549.50 kJ/mol812.10 kJ/mol
375.7
148700
👆🏻
20th Energy Level
549.00 kJ/mol812.00 kJ/mol
0
171200
👆🏻
21st Energy Level
549.50 kJ/mol812.10 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
549.00 kJ/mol812.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
549.50 kJ/mol812.10 kJ/mol
357.6
198800
👆🏻
24th Energy Level
549.50 kJ/mol812.10 kJ/mol
297.3
195200
👆🏻
25th Energy Level
549.00 kJ/mol812.10 kJ/mol
0
121900
👆🏻
26th Energy Level
549.50 kJ/mol812.10 kJ/mol
357.6
127700
👆🏻
27th Energy Level
549.50 kJ/mol812.10 kJ/mol
0
133800
👆🏻
28th Energy Level
549.50 kJ/mol812.10 kJ/mol
297.3
139800
👆🏻
29th Energy Level
549.50 kJ/mol812.10 kJ/mol
0
148100
👆🏻
30th Energy Level
549.50 kJ/mol812.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.64 g/amp-hr3.90 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
2.59 eV4.50 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Ionization, Radioactive Isotopes, Solubility
Atomic Number
3884
3
117
👆🏻
Electron Configuration
[Kr] 5s2
[Xe] 4f14 5d10 6s2 6p4
Crystal Structure
Face Centered Cubic (FCC)
Monoclinic (MON)
Crystal Lattice
Atom
Number of Protons
3884
3
117
👆🏻
Number of Neutrons
50125
4
285
👆🏻
Number of Electrons
3884
3
117
👆🏻
Radius of an Atom
Atomic Radius
215.00 pm168.00 pm
0
348
👆🏻
Covalent Radius
195.00 pm140.00 pm
0
260
👆🏻
Van der Waals Radius
249.00 pm197.00 pm
0
348
👆🏻
Atomic Weight
87.62 amu209.00 amu
6.94
294
👆🏻
Atomic Volume
33.70 cm3/mol22.23 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
25.70 (-eV)9.30 (-eV)
0
392.42
👆🏻
Lattice Constant
608.49 pm335.90 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
1.571.46
0.423
1.9
👆🏻
Density
Density At Room Temperature
2.64 g/cm39.20 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
2.38 g/cm39.40 g/cm3
0.512
41
👆🏻
Tensile Strength
170.00 MPa50.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
121.00 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
6.03 GPa24.00 GPa
1.3
222
👆🏻
Bulk Modulus
11.00 GPa46.00 GPa
0
462
👆🏻
Young's Modulus
15.70 GPa46.00 GPa
0
528
👆🏻
Poisson Ratio
0.280.23
0.032
0.47
👆🏻
Other Mechanical Properties
-
-
Magnetic Characteristics
Specific Gravity
2.649.32
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Nonmagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
-
Conductor
Resistivity
132.00 nΩ·m0.40 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.08 106/cm Ω0.02 106/cm Ω
0
0.63
👆🏻
Electron Affinity
5.03 kJ/mol183.30 kJ/mol
0
222.8
👆🏻
Specific Heat
0.30 J/(kg K)0.12 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
26.40 J/mol·K26.40 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
35.40 W/m·K20.00 W/m·K
0
429
👆🏻
Critical Temperature
1,050.00 K527.00 K
26.3
3695
👆🏻
Thermal Expansion
22.50 µm/(m·K)23.50 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
150.00 kJ/mol60.30 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
9.16 kJ/mol13.00 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
163.20 kJ/mol134.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
55.00 J/mol.K41.10 J/mol.K
9.5
198.1
👆🏻