Antimony Sb (Element 51) of Periodic Table

51 Sb (Antimony Element)

Flashcard of Antimony

About Antimony Element

It is exist in two forms,
(1) The metallic form is silvery, bright, hard and brittle
(2) The non metallic form is a grey powder.
Antimony is a poor conductor of heat and electricity.

Antimony element
Antimony Metal Piece
Antimony powder
Antimony Powder (Non-metallic)


CAS Number: CAS7440-36-0
CID Number:  CID5354495
RTECS Number:  RTECSCC4025000

Basic Properties of Antimony Element

Pronunciation:  an-ta-ma-nee
Appearance:  Silvery lustrous gray
Alternate Names:  Stibium
Names of Allotropes:  White Antimony, Yellow Antimony, Black Antimony
Mass Number:  122
Standard Atomic weight: 121.760  g/mol
Atomic number (Z):  51
Electrons: 51
Protons:  51
Neutrons:  71
Period:  5
Group:  15
Block:  p
Element category:  Metalloid (semi-metal)
Electrons per shell:  K2, L8, M18, N18, O5
Electron configuration:  1s22s22p63s23p63d104s24p64d105s25p3

Antimony electron configuration
Antimony Electron Configuration

Thermal Properties of Antimony

Phase:  Solid
Melting point:  903.78 K (630.63 oC, 1167.13 oF)
Boiling point:   1908 K (1635 oC, 2975 oF)
Debye temperature:  -73.15 K (99.67 oC,200 oF)
Fusion heat:  19.79 kJ/mol
Vaporization heat:  193.43 kJ/mol
Specific heat:  207 J/(kg K)
Molar heat capacity:  25.23 J/(mol.K)
Thermal expansion:  11  μm/(m∙K)
Thermal conductivity:  24.4 W/(m∙K)

Electrical properties of Antimony

Electrical conductivity:  2.5×106 S/m
A Electrical resistivity:  417 nΩ∙m
A Electrical type:  Conductor (poor conductor)

Magnetic Properties of Antimony

A Magnetic type:  Diamagnetic
Magnetic susceptibility (xmol):  -99×10-6 cm3/mol
Volume magnetic susceptibility:  0.000073
Mass magnetic susceptibility:  10.9×10-9 m3/kg
Molar magnetic susceptibility:  1.327×10-9 m3/mol

Physical Properties of Antimony

Density:  6.697 g/cm3 (In solid)  6.53 g/cm3 (In Liquid)
Molar volume:  0.00001818 m3/mol
Young’s modulus:  55 GPa
Shear modulus:  20 GPa
Mohs Hardness:  3
Bulk modulus:  42 GPa
Brinell hardness:  294 MPa
Sound Speed:  3420 m/s

Atomic Properties of Antimony 

Oxidation states:  5, 4, 3,2, 1, -1, -2, -3
Valence Electrons:  5s2 5p3
Ion charge:  Sb3+ Sb5+
The ionization potential of an atom:  8.35
Ionization energies:  1st: 834 kJ.mol 2nd: 1594.9 kJ/mol 3rd: 2440 kJ/mol
Ionic radius:   76 pm
Atomic radius:  206 pm (Van der Waals)
Covalent radius:  139±5 pm
Filling Orbital:  5p3
Crystal structure:  Rhombohedral
Lattice constant:  430.7, 430.7, 1127.3 pm
Grid parameters:  a(Hex)=4.307 Å c(Hex)=11.27 Å
Attitude c/a:  2.62
Space Group Name:  R_3m
Space Group Number:  166


Reactivity of Antimony

Electronegativity:  pauling scale: 2.05
Valence:  +5
Electron affinity:  103.2 kJ/mol

Nuclear Properties of Antimony Element

Half Life:  Stable (Infinity) 
Lifetime:  Stable (Infinity)
Quantum Number:  4S3/2
Neutron cross section (Brans):  5.4
Neutron Mass Absorption:  0.0016
Isotopes:  121Sb 123Sb 125Sb 

Isotope Abundance (%) Atomic Mass g/mol Half Life (t1/2)
121Sb 57.21 120.904 Stable
123Sb 42.79 122.904 Stable
125Sb Syn 2.7582 y

Chemical Reactions

Antimony reacts with in air and  form trioxide antimony:
4 Sb (s) + 3 O2 (g) → 2 Sb2O3 (s) (Flame is Bluish white)

At red heat, Reacts with water and form Antimony (lll) oxide: Sb reacts slowly at ambient temperature.
2 Sb (s) + 3 H2O (g) → Sb2O3 (s) + 3 H2 (g)
Sb (III) as the tetra chloro complex can react with water and forming the precipitate Antimony oxychloride (SbOCl):
[SbCl4] (aq) + H2O (l) ⇌ SbOCl (s) [white] + 3 Cl (aq) + 2 H+ (aq)
The Precipitate can be dissolved by alkali:
SbOCl (s) + 2 OH (aq) + H2O (l) ⇌ [Sb(OH)4] (aq) + Cl (aq)
2 SbOCl (s) + 2 C4H6O6 (aq) ⇌ [Sb2(C4H6O)2]2- (aq) + 4 H+ (aq) + 2 Cl (aq) + 2 H2O (l)

Reacts with all Halogens:
2 Sb (s) + 3 F2 (g) → 2 SbF3 (s)  [white]  (Antimony (lll) fluoride)
2 Sb (s) + 3 Cl2 (g) → 2 SbCl3 (s)  [white]  (Antimony (lll) chloride)
2 Sb (s) + 3 Br2 (g) → 2 SbBr3 (s)  [white]  (Antimony (lll) bromide)
2 Sb (s) + 3 I2 (g)  →  2 SbI3 (s)     [Red]  (Antimony (lll) iodide)  

Sb React with acid:
Antimony (Sb) dissolved in hot concentrated sulphuric acid (H2SO4) or nitric acid (HNO3) and forming a Sb(III) solutions. The sulphuric acid reaction produces Sulphur dioxide SO2 gas. Antimony does not react with hydrochloric acid (HCl) in the absence of oxygen.
Antimony can be Separated from the crude antimony sulfide by reduction with scrap iron:
Sb2S3 + 3 Fe → 2 Sb + 3 FeS
Antimony is Separated from the oxide by a carbothermal reduction:
2 Sb2O3 + 3 C → 4 Sb + 3 CO2
The lower-grade ores are reduced in blast furnaces while the higher-grade ores are reduced in reverberatory furnaces.

Antimony History

Naming:  Greek: anti (not) monos (alone); Symbol for Latin stibium
Discovery:  Before 800 CE

Antimony Uses

Pure antimony used in electronics industry to make certain types of semiconductor devices, such as infrared detector, diodes and hall-effect devices.

A Antimony is alloyed with lead  to improve their hardness and mechanical strength.
A Antimony alloys are used in Batteries, antifriction alloys (such as Babbitt metal), type metal (linotype printing machines), electrical cable sheathing, small arms and tracer bullets.

Antimony is mainly used in the trioxide for  make flame-proofing compounds, paint, glass art, and as an opacifier (Titanium dioxide, TiO2) in enamel.

Biological role:  Antimony and many of its compounds are toxic. Inhalation of antimony trioxide  is considered harmful and suspected of causing cancer. 

Abundance of Antimony 

Antimony is not an abundant element, but is found in over 100 mineral species.
Antimony can be found as the native metal.
It is most often found in Stibnite (is a sulfide mineral with the formula, Sb2S3)  Sometimes called antimonite.

It is extracted by roasting the antimony trisulfide (Sb2S3) to the oxide, and then reducing with carbon.

Annual world wide production is around 53,000 tons.
4×10-8% (In Universe)
1.2×10-5% (In Meteorites)
1×10-7% (In Sun)
0.000028% (In Earth’s Crust)
2×10-8% (In Oceans)

Stibnite mineral
Stibnite or Antimonite (Sulfide mineral)

World’s Top 3 producers of Antimony

1) China (77 %)
2) Russia (7 %)
3) Tajikistan (6 %)

World’s Top 3 Reserve holders of Antimony

1) China
2) Russia
3) Bolivia


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