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Element 31 - Gallium (Ga)
From
Gallia
, the old name for France; discovered 1875. A metal that melts in the hand, it is one of the few that expands as it freezes, as do nonmetals and most gases. Its high boiling point (2478 K) makes it ideal for recording temperatures that would vaporize a thermometer.
Properties
Atomic Number
:
31
Atomic Weight
:
69.723
Electron Configuration
(at ground state):
1s
2
2s
2
2p
6
3s
2
3p
6
3d
10
4s
2
4p
1
Oxidation States
(Bold most stable):
+3
Boiling Point
(K):
2478
Melting Point (K):
302.92
Density
(at 300K -- g/cm
3
):
5.91
Atomic Volume (at 300K -- cm
3
/mol)
11.80
Number of stable
isotopes
:
2
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
67 -- 78.2 hours -- orbital
electron capture
72 -- 14.10 hours --
beta particle
(
electron
) emission
Covalent Radius (Å):
1.26
Atomic Radius (Å):
1.41
First
Ionization Potential
(V):
5.999
Electronegativity
(Pauling's):
1.81
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.371
Heat of Vaporization (kJ/mol):
256.06
Heat of Fusion (kJ/mol):
5.59
Electrical Conductivity (at 293K for polycrystalline material -- 10
6
-1
cm
-1
):
1.8
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
40.6
Crystal Structure:
Orthorhombic
Acid
-
Base
Properties:
Amphoteric