Nitrogen vs Phosphorus
Nitrogen is a non-metal (diatomic non-metal); Phosphorus is a non-metal (polyatomic non-metal).
The differences in plain English
- They sit in the same column, group 15, so they have the same number of outer electrons and react in similar ways; the heavier one, Phosphorus, is usually the more reactive of the two if they are metals, and the less reactive if they are non-metals.
- At room temperature Nitrogen is a gas and Phosphorus is a solid.
- An atom of Phosphorus is about 2.2 times heavier than an atom of Nitrogen (30.97 u against 14.01 u).
- Nitrogen pulls electrons more strongly in a bond (electronegativity 3.04 against 2.19).
Side by side
| Nitrogen | Phosphorus | |
|---|---|---|
| Atomic number | 7 | 15 |
| Symbol | N | P |
| Family | Diatomic non-metal | Polyatomic non-metal |
| Group / period | 15 / 2 | 15 / 3 |
| State at room temperature | Gas | Solid |
| Atomic mass | 14.007 u | 30.974 u |
| Density | 1.251 g/L | 1.823 g/cm³ |
| Melting point | -210 °C | – |
| Boiling point | -196 °C | – |
| Electronegativity | 3.04 | 2.19 |
| First ionisation energy | 1402.3 kJ/mol | 1011.8 kJ/mol |
| Electron configuration | [He] 2s2 2p3 | [Ne] 3s2 3p3 |
| Discovered by | Daniel Rutherford | Hennig Brand |
Nitrogen
Take a breath. About 78 per cent of what just entered your lungs was nitrogen, and almost all of it will leave again unchanged. Nitrogen gas is made of pairs of atoms held together by a triple bond, one of the strongest in chemistry. That bond makes nitrogen so stable that most things ignore it, which is exactly why it fills the air rather than reacting away.
- About 78 per cent of the air by volume is nitrogen.
- The triple bond in a nitrogen molecule is one of the strongest chemical bonds known, which is why nitrogen gas is so unreactive.
Phosphorus
Phosphorus was the first element discovered by a person whose name we know, and it arrived with a sense of theatre. In 1669 a German alchemist boiled down vast quantities of urine and obtained a waxy solid that glowed in the dark and burst into flame in air. He named it after the Greek for light-bearer.
- Phosphorus was the first element discovered by a named individual, Hennig Brand, in about 1669.
- White phosphorus glows in the dark because it reacts slowly with oxygen in the air, not because it stores light.
Colour the bubbles by density or melting point and the difference jumps out.
More comparisons
Data from Periodic-Table-JSON (CC BY-SA); temperatures rounded to the nearest degree. Written by Anthony.