Phosphorus

15
P
Group
15
Period
3
Block
p
Protons
Electrons
Neutrons
15
15
16
General Properties
Atomic Number
15
Atomic Weight
30.973762
Mass Number
31
Category
Other nonmetals
Color
Colorless
Radioactive
No
From the Greek phosphoros, light bearing; ancient name for the planet Venus when appearing before sunrise
Crystal Structure
Simple Triclinic
History
Hennig Brand discovered phosphorus in 1669, in Hamburg, Germany, preparing it from urine.

In 1769, Johan Gottlieb Gahn and Carl Wilhelm Scheele showed that calcium phosphate is found in bones, and they obtained elemental phosphorus from bone ash.

Antoine Lavoisier recognized phosphorus as an element in 1777.
Electrons per shell
2, 8, 5
Electron Configuration
[Ne] 3s2 3p3
P
Elemental phosphorus exists in two major forms - white phosphorus and red phosphorus
Physical Properties
Phase
Solid
Density
1.82 g/cm3
Melting Point
317.25 K | 44.1 °C | 111.38 °F
Boiling Point
553 K | 279.85 °C | 535.73 °F
Heat of Fusion
0.64 kJ/mol
Heat of Vaporization
12.4 kJ/mol
Specific Heat Capacity
0.769 J/g·K
Abundance in Earth's crust
0.099%
Abundance in Universe
0.0007%
Red
Image Credits: Images-of-elements
Red phosphorus as powder
CAS Number
7723-14-0
PubChem CID Number
5462309
Atomic Properties
Atomic Radius
98 pm
Covalent Radius
107 pm
Electronegativity
2.19 (Pauling scale)
Ionization Potential
10.4867 eV
Atomic Volume
17.0 cm3/mol
Thermal Conductivity
0.00235 W/cm·K
Oxidation States
-3, -2, -1, 1, 2, 3, 4, 5
Applications
Many fertilisers contain a high proportion of phosphorus and are manufactured from concentrated phosphoric acids.

Phosphorus is used in the manufacture of safety matches, pyrotechnics and incendiary shells.

Phosphorus is also used in steel manufacture and in the production of phosphor bronze.
White phosphorus is highly toxic while red phosphorus is considered non-toxic
Isotopes
Stable Isotopes
31P
Unstable Isotopes
24P, 25P, 26P, 27P, 28P, 29P, 30P, 32P, 33P, 34P, 35P, 36P, 37P, 38P, 39P, 40P, 41P, 42P, 43P, 44P, 45P, 46P