Symbol
Ba
  
Sr
  
Period Number
6
  
5
  
Block
s block
  
s block
  
Element Family
Alkaline Earth
  
Alkaline Earth
  
Space Group Name
Im_ 3m
  
Fm_ 3m
  
Interesting Facts
- Barium oxidizes very easily in the air.
- All toxic compounds of Barium can easily dissolve in water.
- Barium carbonate is used to produce a Rat poison and its other compound Barium nitrate is used in fireworks to produce green color.
  
- Strontium element is softer than Calcium.
- Silvery Strontium turns yellow, if exposed to air.
  
Sources
Earth's crust, Found in Minerals, Mining, Ores of Minerals
  
Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Carl Wilhelm Scheele
  
William Cruickshank
  
Discovery
In 1772
  
In 1787
  
Abundance
  
  
Abundance In Sun
~0.000001 %
  
18
~0.000005 %
  
15
Abundance In Earth's Crust
Uses & Benefits
- It is sued in chemical paint manufacturing and glass manufacturing.
-
Compounds of this metal are toxic; but still the barium sulfate is insoluble and given to patients suffering from digestive disorder.
  
- 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
Ammunition Industry, Automobile Industry, Electrical Industry, Electronic Industry
  
Ammunition Industry, Chemical Industry
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys
  
Alloys
  
Biological Properties
  
  
Toxicity
Low Toxic
  
Non Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
0.07 Blood/mg dm-3
  
15
0.03 Blood/mg dm-3
  
19
In Bone
70.00 p.p.m.
  
9
140.00 p.p.m.
  
7
Boiling Point
1,140.00 °C
  
99+
1,384.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery Gray
  
Silvery White
  
Luster
NA
  
Metallic
  
Hardness
  
  
Speed of Sound
1,620.00 m/s
  
99+
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 Formula
Ba
  
Sr
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
502.90 kJ/mol
  
99+
549.50 kJ/mol
  
99+
2nd Energy Level
965.20 kJ/mol
  
99+
1,064.20 kJ/mol
  
99+
3rd Energy Level
3,600.00 kJ/mol
  
14
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
2.56 g/amp-hr
  
20
1.64 g/amp-hr
  
99+
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
  
Ionization, Radioactive Isotopes, Radioactivity, Solubility
  
Electron Configuration
[Xe] 6s2
  
[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
  
  
Radius of an Atom
  
  
Atomic Weight
137.33 amu
  
99+
Atomic Volume
39.24 cm3/mol
  
5
33.70 cm3/mol
  
6
Adjacent Atomic Numbers
  
  
Valence Electron Potential
21.30 (-eV)
  
99+
25.70 (-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
3.51 g/cm3
  
99+
2.64 g/cm3
  
99+
Density When Liquid (at m.p.)
3.34 g/cm3
  
99+
2.38 g/cm3
  
99+
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Bulk Modulus
Not Available
  
Poisson Ratio
Not Available
  
Other Mechanical Properties
NA
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Superconductor
  
NA
  
Resistivity
332.00 nΩ·m
  
13
132.00 nΩ·m
  
24
Electrical Conductivity
0.03 106/cm Ω
  
40
0.08 106/cm Ω
  
26
Electron Affinity
13.95 kJ/mol
  
36
5.03 kJ/mol
  
38
Specific Heat
0.20 J/(kg K)
  
30
0.30 J/(kg K)
  
18
Molar Heat Capacity
28.07 J/mol·K
  
12
26.40 J/mol·K
  
28
Thermal Conductivity
18.40 W/m·K
  
99+
35.40 W/m·K
  
37
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
20.60 µm/(m·K)
  
22
22.50 µm/(m·K)
  
18
Enthalpy
  
  
Enthalpy of Vaporization
140.00 kJ/mol
  
99+
150.00 kJ/mol
  
99+
Enthalpy of Fusion
7.66 kJ/mol
  
99+
9.16 kJ/mol
  
38
Enthalpy of Atomization
175.70 kJ/mol
  
99+
163.20 kJ/mol
  
99+
Standard Molar Entropy
62.50 J/mol.K
  
20
55.00 J/mol.K
  
26