Q.White and yellow phosphorous are -

Phosphorus exists in several allotropic forms. White phosphorus is a soft, waxy, poisonous, translucent solid made of discrete tetrahedral $P_4$ molecules; the P-P-P bond angle is only $60°$, so the molecule is highly strained, making white phosphorus far more reactive than the other allotropes and prone to spontaneous combustion in air. Heating white phosphorus in an inert atmosphere converts it to red phosphorus, a polymeric, less strained, non-poisonous, and much less reactive chain-like solid formed by breaking one P-P bond per tetrahedron and linking $P_4$ units together, which is why nitrogen (which cannot form such extended chains because it lacks accessible d orbitals and large enough atoms for strong catenation) shows far less catenation than phosphorus. White phosphorus reacts with hot concentrated NaOH solution …