Periodic Table

Phosphorus

Nonmetal

Quick Facts about Phosphorus

Si
  • solid- state of matter at room temperature
  • Stable- has at least one stable isotope
  • +5, +3, -3- common oxidation states in compounds
  • CUB- crystal structure, atomic arrangement in solid form
S

Phosphorus (P) is element 15 on the periodic table. Atomic mass of P: 30.9740 u. P is in period 3, group 15. Melting point of P: 317.30 K.Density of P: 1.82 g/cm³.

Why Phosphorus Matters

The element in your DNA, bones, and every living cell

In Your Home

  • Matches (phosphorus tips)
  • Fertilizers for garden plants
  • Soft drinks (phosphoric acid)
  • Detergents (phosphates)

Industry Uses

AgriculturePhosphate fertilizers essential for crop production
FoodPhosphoric acid in soft drinks, food additives
ChemicalPesticides, flame retardants, plasticizers
TechSemiconductors, LED phosphors

In Your Body

✓ Essential for life

Second most abundant mineral in body after calcium. Essential for DNA/RNA, ATP energy, and bones (85% of body phosphorus). Part of cell membranes.

Safety: Excess phosphorus from processed foods may harm kidneys and bones. White phosphorus is extremely toxic and flammable.

Discovery of Phosphorus

Discovered by Hennig Brand in Germany, 1669

Name origin: Greek: phosphoros, (bringer of light).

History & Events

1669
Discovery
Hennig Brand discovered phosphorus while boiling urine trying to make gold!
1830
Friction Matches
Charles Sauria invented white phosphorus matches (later banned due to 'phossy jaw')
1840
Fertilizer Use
Justus von Liebig identified phosphorus as essential plant nutrient

About Phosphorus

Non-metallic element belonging to group 15 of the periodic table. Has a multiple allotropic forms. Essential element for living organisms. It was discovered by Brandt in 1669.

Atomic Properties of P

Atomic Number of P
15
Atomic Mass of P
30.9740 u
Electron Configuration
[Ne] 3s2 3p3
Electronegativity
2.19
Block
p-block
Group
15
Period
3

Physical Properties of P

Phase (STP)
solid
Melting Point of P
317.30 K
Boiling Point of P
553.70 K
Density of P
1.8230 g/cm3

Thermal Properties

Heat of Fusion
2.51 kJ/mol
Heat of Vaporization
49.80 kJ/mol
Specific Heat
0.77 J/g·K
Molar Heat Capacity
23.82 J/mol·K

Atomic Radii

Calculated
100 pm
Covalent
111 pm
Van der Waals
180 pm
Metallic
110 pm

Common Misconceptions

Wrong:Phosphorus glows because it's radioactive.
Correct:White phosphorus glows due to slow oxidation (chemiluminescence), not radioactivity.
Wrong:Phosphorus is only in bones.
Correct:Phosphorus is in every cell! DNA, RNA, ATP, and cell membranes all contain phosphorus.
Wrong:All phosphorus is dangerous.
Correct:Red phosphorus (in match striking surfaces) is safe. White/yellow phosphorus is extremely dangerous.

Allotropes of Phosphorus

Phosphorus exists in 4 different structural forms (allotropes), each with unique properties.

White Phosphorus (P4)

Waxy, translucent solid that glows in dark

Structure:Tetrahedral P4 molecules
Properties:Highly toxic, pyrophoric (ignites in air), stored under water
Uses:Chemical warfare agent (historical), smoke screens, rodenticides

Red Phosphorus

Stable, non-toxic red powder

Structure:Polymeric chains derived from P4
Properties:Stable in air, much less toxic than white phosphorus
Uses:Match striker strips, flame retardants, semiconductors

Black Phosphorus

Most stable form, graphite-like appearance

Structure:Layered structure similar to graphite (phosphorene layers)
Properties:Semiconductor, can be exfoliated to 2D phosphorene
Uses:Electronics research, potential transistors, batteries

Violet Phosphorus

Also called Hittorf's phosphorus

Structure:Complex tubular structure
Properties:Very stable, crystalline, non-toxic

Isotopes of Phosphorus

Phosphorus has 1 naturally occurring isotope, plus 1 notable radioactive isotope.

IsotopeAtomic Mass (u)AbundanceHalf-LifeDecay Mode
3115P (P-31)Phosphorus-31 isotope30.973762100.00%——
3215P (P-32)Phosphorus-32 isotope31.973907270%14.28 daysβ⁻

Data source: NIH PubChem (aggregated from IUPAC, NIST)

Isotope Applications

Isotopes of Phosphorus have important real-world applications in science and industry.

Industrial Applications

32P was added to tires in the 1950s by Goodrich Laboratories to help determine the location and depth of tire wear in performance tests [136].

Medical Applications

Beta emissions from the radioactive isotope 32P can be used in drug therapy of cancerous bone masses. By injecting a patient with a 32P pharmaceutical, tumors and other cells can be targeted for cell death, which also helps to alleviate pain [137], [138]. For example, Polycythemia vera is the condition of having excess red blood cells in the bone marrow: 32P can be used to treat this condition by reducing the number of red blood cells. However, there is no cure for this condition [139]. Using a 32P labeled bio-silicone product, 32P has been used as the radioactive target in brachytherapy of solid tumors in the lung [140]. Depending on the type of 32P-labeled compound (antibody or pharmaceutical drug), when it is ingested or injected into the body, specific body parts (blood, tumors, joints, or bones) can be targeted for visualization and imaged using a gamma camera. This is useful for imaging cancer sites and for treatment monitoring of oncologic patients [133], [134], [138].

Abundance

Earth's Crust
1.1 g/kg
Seawater
60.00 μg/kg

Uses

Used in the production of fertilizers and detergents. Some is used in fireworks, safety matches, and incendiary weapons. Also some applications for it and some of its compounds which glow in the dark.

Sources

Found most often in phosphate rock. Pure phosphorus is obtained by heating a mixture of phosphate rock, coke, and silica to about 1450 °C.

Geochemistry

Goldschmidt
litophile

Test Your Knowledge

Loading quiz...

Learn More

Related Content

Study Topics

Lewis StructuresMolecular Shape