Nitrogen and phosphorus are both in Group 15 of the periodic table, but they show different chemical behavior because of differences in size, electronegativity, and bonding. Here’s a comparison:
- Atomic size and electronegativity:
- Nitrogen is smaller and more electronegative. It forms strong triple bonds in N₂, making it very stable and less reactive.
- Phosphorus is larger and less electronegative. Its P–P bonds are weaker, so it is more reactive than nitrogen.
- Oxidation states:
- Nitrogen commonly shows -3, +3, +5 oxidation states.
- Phosphorus also shows -3, +3, +5, but the +5 state is more stable for phosphorus than for nitrogen.
- Hydrides:
- Nitrogen hydride (NH₃): Stable, forms hydrogen bonds, very basic.
- Phosphorus hydride (PH₃): Less stable, weaker hydrogen bonding, less basic.
- Oxides and acids:
- Nitrogen oxides are mostly gases and can be acidic or neutral.
- Phosphorus oxides are solids and strongly acidic when dissolved in water.
- Reactivity with oxygen:
- Nitrogen is less reactive at room temperature due to the strong N≡N triple bond.
- Phosphorus ignites more easily in air because P–P bonds are weaker.
In short:
- Nitrogen is less reactive, forms strong multiple bonds, and its compounds are often gaseous.
- Phosphorus is more reactive, forms weaker bonds, and its compounds are often solid and more acidic.