what is meant by pyrophoric nature of a substance
A Substance is said to have pyrophoric ntaure when it ignites spontaneously in air i.e. it undergoes a kind of spontaneous and very violent explosion when exposed to oxygen, water, or moisture in the air. Such substances are often water-reactive also and ignite when they contact water or humid air. The pyrophoric substances have an auto ignition temperature below room temperature and often require a very less contact with air or water in order to spontaneously ignite.