Reactive nonmetals
Phosphorus
A reactive nonmetal vital to DNA and energy transfer.
Atomic #15Mass30.974Blockp-blockPeriod3Group15
P15 · 30.974
3D Atom Explorer
Inside the Phosphorus atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Phosphorus atom step by step.
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Electron configuration
[Ne] 3s2 3p3
A neutral Phosphorus atom has 15 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Shell 12 e⁻Shell 28 e⁻Shell 35 e⁻
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Properties
Physical & atomic properties
- State (room temp)
- Solid
- Melting point
- 317 K (44 °C)
- Boiling point
- 554 K (281 °C)
- Density
- 1.82 g/cm³
- Electronegativity
- 2.19 Pauling
- Atomic radius
- 100 pm
- 1st ionization energy
- 1012 kJ/mol
- Category
- Reactive nonmetals
History
Discovery & naming
- Discovered
- 1669
- Discovered by
- Hennig Brand
- Origin of name
- Greek 'phosphoros', meaning light-bearer.
Notable uses
Fertilizers, matches, and DNA and energy molecules in life.
Cosmic origin
Where Phosphorus comes from
Stellar fusion and dying stars
A minor product of neon and oxygen burning inside massive stars.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 15
- Atomic mass
- 30.974
- Category
- Reactive nonmetals
- Group · Period
- 15 · 3
- Block
- p-block
- Shells
- 2 · 8 · 5