Symbol
Ga
  
Tl
  
Period Number
4
  
6
  
Block
p block
  
p block
  
Element Family
Post-Transition
  
Post-Transition
  
Space Group Name
Cmca
  
P63/mmc
  
Interesting Facts
- A gram of Gallium metal can be bought for only three dollars.
- Gallium metal found in ores of following things Coal, Bauxite, Diaspore, Sphalerite, Germanite and Zinc.
  
- Compounds of Thallium metal are highly Toxic.
- Thallium metal is being suspected as a human carcinogen.
  
Sources
Earth's crust, Found in Minerals, Mining, Ores of Minerals
  
Found As a By-product, Ores of metals, Ores of Minerals
  
History
  
  
Who Discovered
Lecoq de Boisbaudran
  
William Crookes
  
Discovery
In 1875
  
In 1861
  
Abundance
  
  
Abundance In Sun
~0.000004 %
  
16
~0.0000001 %
  
26
Abundance In Earth's Crust
Uses & Benefits
- Gallium arsenide is a very important component of many semiconductors and led manufacturing.
- Gallium nitride is also know as a semiconductor and it is used in Blu-ray technology, mobile smartphones and LED.
  
- Thallium is a toxic metal and hence it has limited uses. Thallium metal is mostly used for producing photoelectric cells.
- In thermometer’s mercury alloy has 8% of thallium, as it has a melting point lower than 20°C.
  
Industrial Uses
Electrical Industry, Electronic Industry
  
Chemical Industry
  
Medical Uses
Surgical Instruments Manufacturing
  
Medical Research
  
Other Uses
Alloys
  
Alloys
  
Biological Properties
  
  
Toxicity
Non Toxic
  
Highly Toxic
  
Present in Human Body
Yes
  
Yes
  
In Blood
0.08 Blood/mg dm-3
  
13
0.00 Blood/mg dm-3
  
34
In Bone
Not Available
  
0.00 p.p.m.
  
33
Boiling Point
2,403.00 °C
  
99+
1,457.00 °C
  
99+
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Silvery White
  
Luster
Metallic
  
NA
  
Hardness
  
  
Speed of Sound
2,740.00 m/s
  
31
818.00 m/s
  
99+
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
Ga
  
Tl
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
578.80 kJ/mol
  
99+
589.40 kJ/mol
  
99+
2nd Energy Level
1,979.30 kJ/mol
  
13
1,971.00 kJ/mol
  
14
3rd Energy Level
2,963.00 kJ/mol
  
28
2,878.00 kJ/mol
  
32
4th Energy Level
6,180.00 kJ/mol
  
8
Not Available
  
Electrochemical Equivalent
0.87 g/amp-hr
  
99+
7.63 g/amp-hr
  
2
Other Chemical Properties
Ionization, Radioactive Isotopes
  
Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Ar] 3d10 4s2 4p1
  
[Xe] 4f14 5d10 6s2 6p1
  
Crystal Structure
Orthorhombic (ORTH)
  
Hexagonal Close Packed (HCP)
  
Crystal Lattice
ORTH-Crystal-Structure-of-Gallium.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
11.80 cm3/mol
  
99+
17.20 cm3/mol
  
31
Adjacent Atomic Numbers
  
  
Valence Electron Potential
69.70 (-eV)
  
19
9.60 (-eV)
  
99+
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, 2 π/3
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
5.91 g/cm3
  
99+
11.85 g/cm3
  
31
Density When Liquid (at m.p.)
6.10 g/cm3
  
99+
11.22 g/cm3
  
13
Tensile Strength
Not Available
  
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Elasticity properties
  
  
Shear Modulus
Not Available
  
Bulk Modulus
Not Available
  
Other Mechanical Properties
NA
  
Ductile, Sectile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Diamagnetic
  
Diamagnetic
  
Electrical Properties
  
  
Electrical Property
Semiconductor
  
Conductor
  
Resistivity
270.00 nΩ·m
  
15
Electrical Conductivity
0.07 106/cm Ω
  
29
0.06 106/cm Ω
  
32
Electron Affinity
28.90 kJ/mol
  
31
19.20 kJ/mol
  
32
Specific Heat
0.37 J/(kg K)
  
16
0.13 J/(kg K)
  
39
Molar Heat Capacity
25.86 J/mol·K
  
35
26.32 J/mol·K
  
29
Thermal Conductivity
40.60 W/m·K
  
34
46.10 W/m·K
  
33
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
18.00 µm/(m·K)
  
24
29.90 µm/(m·K)
  
12
Enthalpy
  
  
Enthalpy of Vaporization
256.10 kJ/mol
  
36
162.10 kJ/mol
  
99+
Enthalpy of Fusion
5.59 kJ/mol
  
99+
4.27 kJ/mol
  
99+
Enthalpy of Atomization
276.10 kJ/mol
  
39
179.90 kJ/mol
  
99+
Standard Molar Entropy
40.80 J/mol.K
  
38
64.20 J/mol.K
  
19