Element 15
Phosphorus
Nonmetals
Phosphorus (P) is in the p-block of the periodic table — group 15, period 3.
Phosphorus is a chemical element with symbol P and atomic number 15.
Key data
- Atomic number
- 15
- Atomic mass
- 30.974 u
- Group / Period
- 15 / 3
- Block
- p-block
- Phase at STP
- Solid
- Density
- 1.823 g/cm³
- Melting point
- —
- Boiling point
- —
- Electron configuration
- [Ne] 3s2 3p3
Periodic table block
Phosphorus is in the p-block (group 15, period 3). Elements land in the p-block when their highest-energy electrons fill a p subshell — this region holds most nonmetals, the metalloids, and the metals on the right of the table.
New to this? Periodic table blocks explained: s, p, d, and f
Common uses
- •Match heads
- •DNA backbone
- •Fertilizers
Discovery
Year: 1669
Discovered by: Hennig Brand
Frequently asked questions
What is the atomic number of Phosphorus?
Phosphorus has atomic number 15. Its symbol is P and its atomic mass is 30.974 u.
What category of element is Phosphorus?
Phosphorus is classified as nonmetals. It sits in group 15, period 3 of the periodic table.
What block of the periodic table is Phosphorus in?
Phosphorus is in the p-block (group 15, period 3). Its highest-energy electrons occupy the p subshell — you can see this in its electron configuration, [Ne] 3s2 3p3.
What is Phosphorus used for?
Common uses of Phosphorus include: Match heads, DNA backbone, Fertilizers.
When was Phosphorus discovered?
Phosphorus was discovered in 1669 by Hennig Brand.
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