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15P30.974
Polyatomic Non-Metalp-block

Phosphorus

Element 15 on the periodic table, symbol P, group 15, period 3.

Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms, white phosphorus and red phosphorus, but due to its high reactivity, phosphorus is never found as a free element on Earth. Instead phosphorus-containing minerals are almost always present in their maximally oxidised state, as inorganic phosphate rocks.

Appearance: colourless, waxy white, yellow, scarlet, red, violet, black

Properties

Atomic Number
15
Atomic Mass
30.9738 u
Group
15
Period
3
Block
p-block
Category
Polyatomic Non-Metal
State at 25 °C
Solid
Melting Point
Not measured
Boiling Point
Not measured
Density
1.823 g/cm³
Atomic Radius
100 pm
Electronegativity
2.19
Oxidation States
-3, +3, +5
Abundance in Crust
1,050 mg/kg
Discovered
1669
Discovered By
Hennig Brand

Electron Configuration

[Ne] 3s2 3p3

1s2 2s2 2p6 3s2 3p3

Ionisation Energies (kJ/mol)

  1. 1. 1,011.8
  2. 2. 1,907
  3. 3. 2,914.1
  4. 4. 4,963.6
  5. 5. 6,273.9
  6. 6. 21,267
  7. 7. 25,431
  8. 8. 29,872

Elements near Phosphorus

Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.

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