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Strontium vs Actinium


Actinium vs Strontium


Periodic Table

Symbol
Sr  
Ac  

Group Number
2  
16
3  
15

Period Number
5  
7  

Block
s block  
f block  

Element Family
Alkaline Earth  
Actinide  

CAS Number
7440246  
99+
7440348  
99+

Space Group Name
Fm_ 3m  
Fm_ 3m  

Space Group Number
225.00  
3
225.00  
3

Facts

Interesting Facts
  • Strontium element is softer than Calcium.
  • Silvery Strontium turns yellow, if exposed to air.
  
Actinium glows in the dark due to its radioactivity.  

Sources
Found in Minerals, Mining, Ores of Minerals  
Obtained by Treating Radium with Neutrons, Ores of metals  

History
  
  

Who Discovered
William Cruickshank  
Friedrich Oskar Giesel  

Discovery
In 1787  
In 1902  

Abundance
  
  

Abundance In Universe
0.00 %  
15
0.00 %  
34

Abundance In Sun
0.00 %  
15
0.00 %  
26

Abundance In Meteorites
0.00 %  
15
0.00 %  
99+

Abundance In Earth's Crust
0.04 %  
10
0.00 %  
99+

Abundance In Oceans
0.00 %  
4
0.00 %  
99+

Abundance In Humans
0.00 %  
8
0.00 %  
24

Uses

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.
  
  • Actinium metal has a great source of alpha rays but it is hardly used outside research purpose.
  

Industrial Uses
Ammunition Industry, Chemical Industry  
-  

Medical Uses
-  
-  

Other Uses
Alloys  
Alloys, Nuclear Research, Research Purposes  

Biological Properties
  
  

Toxicity
Non Toxic  
Toxic  

Present in Human Body
Yes  
No  

In Blood
0.03 Blood/mg dm-3  
19
0.00 Blood/mg dm-3  
40

In Bone
140.00 p.p.m.  
7
0.00 p.p.m.  
99+

Physical

Melting Point
769.00 °C  
99+
1,227.00 °C  
38

Boiling Point
1,384.00 °C  
99+
3,200.00 °C  
27

Appearance
  
  

Physical State
Solid  
Solid  

Color
Silvery White  
Silvery White  

Luster
Metallic  
-  

Hardness
  
  

Mohs Hardness
1.50  
19
6.50  
5

Brinell Hardness
110.00 MPa  
99+
70.00 MPa  
99+

Vickers Hardness
15.00 MPa  
99+
260.00 MPa  
99+

Speed of Sound
4,170.00 m/s  
23
3,430.00 m/s  
32

Optical Properties
  
  

Refractive Index
1.43  
39
1.00  
99+

Reflectivity
65.00 %  
18
62.00 %  
21

Allotropes
No  
No  

α Allotropes
-  
-  

β Allotropes
-  
-  

γ Allotropes
-  
-  

Chemical

Chemical Formula
Sr  
Ac  

Isotopes
  
  

Known Isotopes
27  
12
29  
10

Electronegativity
  
  

Pauling Electronegativity
0.95  
99+
1.10  
99+

Sanderson Electronegativity
0.72  
99+
1.10  
38

Allred Rochow Electronegativity
0.99  
38
1.00  
37

Mulliken-Jaffe Electronegativity
1.00  
99+
1.10  
99+

Allen Electronegativity
0.96  
99+
1.10  
99+

Electropositivity
  
  

Pauling Electropositivity
3.05  
7
2.90  
10

Ionization Energies
  
  

1st Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

2nd Energy Level
1,064.20 kJ/mol  
99+
1,170.00 kJ/mol  
99+

3rd Energy Level
4,138.00 kJ/mol  
10
1,900.00 kJ/mol  
99+

4th Energy Level
5,500.00 kJ/mol  
22
4,700.00 kJ/mol  
33

5th Energy Level
6,910.00 kJ/mol  
30
4,990.00 kJ/mol  
99+

6th Energy Level
8,760.00 kJ/mol  
26
5,750.00 kJ/mol  
99+

7th Energy level
10,230.00 kJ/mol  
19
5,750.00 kJ/mol  
99+

8th Energy Level
11,800.00 kJ/mol  
19
5,750.00 kJ/mol  
99+

9th Energy Level
15,600.00 kJ/mol  
17
4,990.00 kJ/mol  
99+

10th Energy Level
17,100.00 kJ/mol  
19
4,990.00 kJ/mol  
99+

11th Energy Level
31,270.00 kJ/mol  
6
4,990.00 kJ/mol  
99+

12th Energy Level
5,490.00 kJ/mol  
99+
49,900.00 kJ/mol  
21

13th Energy Level
5,490.00 kJ/mol  
99+
4,990.00 kJ/mol  
99+

14th Energy Level
5,490.00 kJ/mol  
99+
4,990.00 kJ/mol  
99+

15th Energy Level
54,900.00 kJ/mol  
99+
49,900.00 kJ/mol  
99+

16th Energy Level
54,900.00 kJ/mol  
99+
49,900.00 kJ/mol  
99+

17th Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

18th Energy Level
5,490.00 kJ/mol  
99+
4,990.00 kJ/mol  
99+

19th Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

20th Energy Level
549.00 kJ/mol  
99+
499.00 kJ/mol  
99+

21st Energy Level
549.50 kJ/mol  
99+
4,990.00 kJ/mol  
25

22nd Energy Level
549.00 kJ/mol  
99+
499.00 kJ/mol  
99+

23rd Energy Level
549.50 kJ/mol  
99+
4,990.00 kJ/mol  
29

24th Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

25th Energy Level
549.00 kJ/mol  
99+
499.00 kJ/mol  
99+

26th Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

27th Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

28th Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

29th Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

30th Energy Level
549.50 kJ/mol  
99+
499.00 kJ/mol  
99+

Electrochemical Equivalent
1.64 g/amp-hr  
99+
2.82 g/amp-hr  
22

Electron Work Function
2.59 eV  
99+
4.38 eV  
23

Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility  
Ionization, Radioactive Isotopes, Radioactivity, Solubility  

Atomic

Atomic Number
38  
99+
89  
29

Electron Configuration
[Kr] 5s2  
[Rn] 6d1 7s2  

Crystal Structure
Face Centered Cubic (FCC)  
Face Centered Cubic (FCC)  

Crystal Lattice
FCC-Crystal-Structure-of-Strontium.jpg#100  
FCC-Crystal-Structure-of-Actinium.jpg#100  

Atom
  
  

Number of Protons
38  
99+
89  
29

Number of Neutrons
50  
99+
138  
17

Number of Electrons
38  
99+
89  
29

Radius of an Atom
  
  

Atomic Radius
215.00 pm  
6
195.00 pm  
9

Covalent Radius
195.00 pm  
15
186.00 pm  
21

Van der Waals Radius
249.00 pm  
11
215.00 pm  
31

Atomic Weight
87.62 amu  
99+
227.00 amu  
25

Atomic Volume
33.70 cm3/mol  
9
22.54 cm3/mol  
20

Adjacent Atomic Numbers
  
  

Previous Element
Rubidium
  
Radium
  

Next Element
Yttrium
  
Thorium
  

Valence Electron Potential
25.70 (-eV)  
99+
38.60 (-eV)  
99+

Lattice Constant
608.49 pm  
6
567.00 pm  
9

Lattice Angles
π/2, π/2, π/2  
π/2, π/2, π/2  

Lattice C/A Ratio
1.57  
40
1.89  
2

Mechanical

Density
  
  

Density At Room Temperature
2.64 g/cm3  
99+
10.00 g/cm3  
40

Density When Liquid (at m.p.)
2.38 g/cm3  
99+
10.07 g/cm3  
40

Tensile Strength
170.00 MPa  
21
65.00 MPa  
33

Viscosity
0.00  
2
0.00  
25

Vapor Pressure
  
  

Vapor Pressure at 1000 K
121.00 (Pa)  
1
0.00 (Pa)  
22

Vapor Pressure at 2000 K
0.00 (Pa)  
38
0.00 (Pa)  
30

Elasticity properties
  
  

Shear Modulus
6.03 GPa  
99+
25.00 GPa  
38

Bulk Modulus
11.00 GPa  
99+
94.00 GPa  
17

Young's Modulus
15.70 GPa  
99+
130.00 GPa  
16

Poisson Ratio
0.28  
17
0.34  
10

Other Mechanical Properties
-  
-  

Magnetic

Magnetic Characteristics
  
  

Specific Gravity
2.64  
99+
10.07  
99+

Magnetic Ordering
Paramagnetic  
Paramagnetic  

Permeability
0.00 H/m  
17
0.00 H/m  
17

Susceptibility
0.00  
35
0.00  
24

Electrical Properties
  
  

Electrical Property
-  
-  

Resistivity
132.00 nΩ·m  
24
5.20 nΩ·m  
99+

Electrical Conductivity
0.08 106/cm Ω  
31
0.15 106/cm Ω  
13

Electron Affinity
5.03 kJ/mol  
99+
33.20 kJ/mol  
34

Thermal

Specific Heat
0.30 J/(kg K)  
18
0.12 J/(kg K)  
99+

Molar Heat Capacity
26.40 J/mol·K  
36
27.20 J/mol·K  
24

Thermal Conductivity
35.40 W/m·K  
38
12.00 W/m·K  
99+

Critical Temperature
1,050.00 K  
99+
1,323.00 K  
99+

Thermal Expansion
22.50 µm/(m·K)  
19
12.10 µm/(m·K)  
99+

Enthalpy
  
  

Enthalpy of Vaporization
150.00 kJ/mol  
99+
120.00 kJ/mol  
99+

Enthalpy of Fusion
9.16 kJ/mol  
99+
14.20 kJ/mol  
28

Enthalpy of Atomization
163.20 kJ/mol  
99+
301.00 kJ/mol  
99+

Standard Molar Entropy
55.00 J/mol.K  
34
56.50 J/mol.K  
33

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