Chem phosphorus!!! (quick)

I want to ask somthing about the atomicity.

My book said it's 4 but my teacher said it isn't, my teacher didn't explain and said it was out of syllabus.

Can anyone explain to me what is the atomicity of phosphorus.

1 個解答

  • 10 年前

    Atomicity of a molecule is the number of atoms present in the molecule. However, the term "atomicity of phosphorus" is very confusing, because phosphorus has several allotropes (forms) that have strikingly different properties, and some of the allotropes are not molecular. The two commonest allotropes are yellow phosphorus and red phosphorus.

    White phosphorus (also known as yellow phosphorus) contains a phosphorus P4 tetrahedron as a structural unit, a thus its atomicity is 4.

    In red phosphorus, one of the P4 bonds is broken, and one additional bond is formed with a neighbouring tetrahedron resulting in a more chain-like structure. The formula of red phosphorus is (P4)n­ where n is varied, and thus the atomicity of red phosphorus is not fixed.

    Violet phosphorus is a polymer of high relative molecular mass. Atomicity is not suitable for polymeric structure.

    Black phosphorus has a structure somewhat resembling that of graphite. Atomicity is also not suitable for such giant structure.

    Diphosphorus, P2, is stable only at high temperatures. The dimeric unit contains a triple bond and is analogous to N2. The diphosphorus allotrope (P2) can be obtained normally only under extreme conditions (for example, from P4 at 1100 K). The atomicity of diphosphorus is 2.

    資料來源: micatkie