Atomic Number
15
Element 15
Phosphorus (P)
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.
Atomic Mass
30.974 u
Category
Nonmetal
Period
3
Group
Group 15: nitrogen group
Phase
solid
Density
1.82 g/cm3
Electron Shells
2, 8, 5
Atomic Structure
Protons: 15. Electrons: 15. Neutrons: Varies by isotope.
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p³
Why Phosphorus Matters
Phosphorus helps connect atomic number 15, nonmetal behavior, period 3 trends, and electron shell structure. Its solid phase, atomic mass of 30.974 u, and electron configuration 1s² 2s² 2p⁶ 3s² 3p³ make it useful for comparing bonding patterns across the periodic table.
Discovery and Occurrence
Phosphorus was discovered 1669 by Hennig Brand. 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.
Safety and Handling Context
Phosphorus is presented here for learning and comparison. Pure elements and laboratory compounds can have hazards that depend on dose, form, and setting.
Related Elements
Frequently Asked Questions
- What is the atomic number of Phosphorus?
- Phosphorus has atomic number 15, which means a neutral atom has 15 protons and 15 electrons.
- What is the chemical symbol for Phosphorus?
- The chemical symbol for Phosphorus is P.
- What category is Phosphorus in?
- Phosphorus is classified as a nonmetal and sits in period 3 of the periodic table.
Explore Phosphorus in 3D
Use the interactive table above to rotate atomic models, compare periodic trends, and move from Phosphorus to neighboring elements without losing your place.