為何磷會在空氣中自然燃燒?

又見廣告, 又是代餐, 又是這公司. 討爾死了.
你見過保健知識那邊的情況嗎? 每一個問題都給三四個這樣的廣告塞滿了,
我見過最誇張的, 一題中有十一個廣告.

回說題目了.
LOK, this is actually related to bond angle and bond-bond repulsion.

phosphorus, or more specifically, white phosphorus, exists as simple molecule, P4.
the optimal bond angle for sp3-hybridized P atom is 109.5 degrees.
however, for P4 which adopts tetrahedral shapes, the bond angle is almost only 60*.
the bond-pairs have strong repulsion against the others, while the high ring strain speeds up breaking of the ring structure. the P4 is not very stable even under room conditions.
as a result, upon spontaneous cleavage of the P-P bond (which has low activation energy), it's prone to rapid oxidation in air, leading to spontaneous ignition.


red phosphorus and others are also allotropes of phosphorus, yet they're stable under air and room conditions. you have to specify which allotropes next time.

關bonding, diploe moment, BP-BP repulsion咩事！？