White phosphorous is more reactive than the nitrogen molecule because the (1) \(\mathrm{P}-\mathrm{P}\) bond in phosphorous is weaker than the \(\mathrm{N} \equiv\) N bond in nitrogen (2) \(\mathrm{P}-\mathrm{P}-\mathrm{P}\) bond angle is \(120^{\circ}\) whereas \(\mathrm{N}_{2}\) is linear (3) Electronegativity of phosphorous is low (4) Ionization energy of phosphorous is greater than of \(\mathrm{N}_{2}\)

The strength of a chemical bond is the measure of its stability and resistance to breaking under stress. In white phosphorus, the molecule consists of a network of P-P single bonds. Compared to multiple bonds, single bonds are inherently weaker because they involve only one shared pair of electrons. This lack of multiple bonding interactions results in a lower bond energy, which means that less energy is required to break the bond.

Specifically, the P-P bond in white phosphorus can be cleaved more easily compared to the N≡N triple bond in nitrogen molecules, which is one of the strongest known chemical bonds due to its three shared pairs of electrons. This contrast in bond strengths is the primary reason for the increased reactivity of white phosphorus; it simply requires less energy to initiate chemical reactions involving the breakage of P-P bonds.

Understanding bond strengths is crucial because it informs chemists how much energy is involved in making or breaking bonds during chemical reactions. In summary, the reactivity of white phosphorus can be largely attributed to its relatively weak P-P bonds.

The nitrogen molecule (N2) is known for having one of the strongest bonds in chemistry due to its robust N≡N triple bond. A triple bond consists of one sigma (σ) bond and two pi (π) bonds. These multiple bonding interactions significantly increase the bond's strength and stability, which is reflected in the high bond-dissociation energy required to break the N≡N bond.

The resistance of nitrogen molecules to reaction under standard conditions is largely because of this strong triple bond. Nitrogen gas is, consequently, quite inert and serves as a stable component of Earth's atmosphere. An understanding of the bond strength can give students insight into why certain molecules are less reactive than others and why the synthesis and decomposition of nitrogen compounds often require specific conditions or catalysts to overcome this formidable bond strength.

Electronegativity is an atom's tendency to attract and hold onto shared electrons in a chemical bond. Phosphorus, being less electronegative than nitrogen, has a reduced capacity to attract bonding electrons towards itself. This lower electronegativity means that the electrons within the P-P bonds in white phosphorus are not held as tightly compared to those in the N≡N bonds of nitrogen.

As a result, the electronic distribution in phosphorus molecules is less stable, which contributes to an increased reactivity. Less electronegative atoms are more willing to participate in chemical reactions by sharing or transferring electrons, which is consistent with the high reactivity of white phosphorus. This demonstrates how electronegativity can influence the reactivity and bonding patterns of elements, a crucial concept for learners studying chemistry.

The spatial arrangement of atoms in a molecule, defined by bond angles, can have implications for the molecule's stability and reactivity. In white phosphorus, the P-P-P bond angles are approximately 120 degrees, a reflection of its tetrahedral geometry. This geometry leads to an equal distribution of atoms in space, reducing the molecule's overall stability in comparison to linear molecules like nitrogen, whose bond angle is 180 degrees.

However, it's important to note that bond angles alone do not fully determine reactivity; they must be considered alongside other factors such as bond strength and electronegativity. In the case of white phosphorus, the reactivity is primarily due to the weaker P-P bonds rather than the bond angles. Teaching this distinction is essential as it helps students understand how various factors contribute to the chemical behavior of substances.