Molecular and Ionic Compound Structure and Properties

2.4 Structure of Metals and Alloys

Essential Knowledge:

*These are taken directly from College Board

• Metallic bonding can be represented as an array of positive metal ions surrounded by delocalized valence electrons (i.e., a “sea of electrons). (SAP-3.D.1)  

• Interstitial alloys form between atoms of different radii, where the smaller atoms fill the interstitial spaces between the larger atoms (e.g., with steel in which carbon occupies the interstices in iron).  (SAP-3.D.2 )

• Substitutional alloys form between atoms of comparable radius, where one atom substitutes for the other in the lattice. (In certain brass alloys, other elements, usually zinc, substitute for copper.)  (SAP-3.D.3 )