P

Phosphorus

IUPAC: Phosphorus

P4 Elements CAS 7723-14-0
Quick Reference
Formula / NotationP4
CAS Number7723-14-0
Molecular Weight30.97
Melting Point44.1
Boiling Point280.5
Density1.82
SolubilityWhite P: insoluble in water, soluble in CS2
AppearanceWhite: waxy colourless-yellow solid; Red: red-violet powder
Also Known AsP, white phosphorus, red phosphorus
CategoryElements

What is Phosphorus?

Phosphorus is a non-metal, atomic number 15, with several allotropes. White phosphorus (P4) is extremely reactive and toxic; red phosphorus is stable. Essential for life - forms backbone of DNA/RNA and ATP. Critical for agricultural fertilisers.

Formula & Notation

P4

IUPAC Name: Phosphorus

Other Names / Synonyms: P, white phosphorus, red phosphorus

Properties & Characteristics

Atomic number: 15. Atomic mass: 30.974 g/mol. Period 3, Group 15. White P: mp 44.1 C, bp 280.5 C, density 1.82 g/cm3, pyrophoric. Red P: mp 590 C, stable. Electronegativity: 2.19. One stable isotope: P-31. Oxidation states: -3, +3, +5.

Physical Data

PropertyValue
Melting Point44.1
Boiling Point280.5
Density1.82
Molecular Weight30.97
SolubilityWhite P: insoluble in water, soluble in CS2
AppearanceWhite: waxy colourless-yellow solid; Red: red-violet powder

Uses & Applications

Fertilisers (superphosphates - most important use). Safety matches (red P on box). Detergents (phosphates). DNA/RNA/ATP (biological). Organophosphate pesticides. Phosphoric acid production. Steel deoxygenation.

Safety Information

White phosphorus: extremely toxic (LD50: 1 mg/kg oral, rat), pyrophoric (ignites in air above 30 C), causes severe burns. Store under water. Red phosphorus: much less toxic but combustible. Phosphine (PH3) gas: extremely toxic.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Phosphorus
Formula P4
CAS Number 7723-14-0
Molecular Weight 30.97
Category Elements
Synonyms P, white phosphorus, red phosphorus

Frequently Asked Questions

Phosphorus is a non-metal, atomic number 15, with several allotropes. White phosphorus (P4) is extremely reactive and toxic; red phosphorus is stable. Essential for life - forms backbone of DNA/RNA and ATP. Critical for agricultural fertilisers.

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