sentence: Red phosphorus can burn but needs to be ignited.
sentences_before: White phosphorus is more reactive than red phosphorus. When white phosphorus is heated in an alkali, it disproportionates to produce hypophosphites and phosphine.
sentences_after: Phosphorus reacts with the halogens to make phosphorus halides. It reacts with some metals to make phosphides.
concept_name: red phosphorus
headings: Phosphorus Properties Chemical properties
categories: Chemical elements