CHM 2353 Lecture Notes - Lecture 12: Lead Poisoning, Air1, Column Chromatography

• School: University of Ottawa
• Department: Chemistry
• Course: CHM 2353
• Professor: Muralee Murugesu

Document Summary

Each atom is bound to all of its nearest neighbour in a crystal by covalent bonds. The whole crystal is one giant molecule called a network solid. The network solid can be 3d or 2 d. Graphite is composed of graphene: a 2-dimensional network solid: formed by stacks of graphene sheets. Graphene is essentially a single layer of aromatics that is the building block for 2d carbon materials. It can be wrapped into 0d bucky calls, rolled into 1d nanotubes, or stacked into 3d graphite: larger distance between layers makes it weaker but more exible. Melting and boiling points decreases down the group. C, si, and ge high melting points are characteristic of network covalent bonding. Sn and pb have a wide liquid range typical of metallic bonding. Group 14 elements can form long chains by creating single bonds between themselves. This ability decreases when we go down the group.