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Element 15 - Phosphorus (P)
From
phosphoros
, or light bearer; discovered 1669; occurs in three major forms--white, red, and, rarely, black. The white, so unstable that it yellows, then reddens in light. glows in the dark--hence "phosphorescence." Phosphates are ingredients of detergents.
Properties
Atomic Number
:
15
Atomic Weight
:
30.97376
Electron Configuration
(at ground state):
1s
2
2s
2
2p
6
3s
2
3p
3
Oxidation States
(Bold most stable):
-3, +3, +4,
+5
Boiling Point
(K):
553
Melting Point (K):
317.3
Density
(at 300K -- g/cm
3
):
1.82
Atomic Volume (at 300K -- cm
3
/mol)
17.0
Number of stable
isotopes
:
1
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
32 -- 14.26 days --
beta particle
(
electron
) emission
Covalent Radius (Å):
1.06
Atomic Radius (Å):
1.28
First
Ionization Potential
(V):
10.486
Electronegativity
(Pauling's):
2.19
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.769
Heat of Vaporization (kJ/mol):
12.4
Heat of Fusion (kJ/mol):
0.63
Electrical Conductivity (at 293K for polycrystalline material -- 10
6
-1
cm
-1
):
10
-16
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
0.235
Crystal Structure:
Monoclinic
Acid
-
Base
Properties:
Slightly acidic