Post on 25-May-2015
description
Part By: Felipe De la Garza
Chemistry House
Silicon (Si)
• Group 4
• 4 valence electrons
• Silica
• Quartz
• Giant Covalent structure
• Tetrahedral arrangement
• Glass: 75% SiO2
Silicon Dioxide
Silicon Dioxide
Electrostatic Attraction in Metallic Bonds
• Delocalized electrons
• "Sea of electrons"
• ⚡
• Metal cations
Conductivity in Metallic Bonds
• Conductivity: ions that are able to move & carry a charge
• Metals have a "pool" of electrons
Copper (Cu)
VSEPRValence Shell Electron Pair Repulsion
• electron pairs formed in the valence shell of atoms repel each other and thus position themselves as far apart as possible
• A molecule's geometry is determined by its electron pairs' repulsion
• Predictions of molecular shape
Negative Charge Centers
• Two NCC
• Molecules with two charge centers will place them 180' from each other. Thus, the molecule has a 180' linear shape
• BeCl2: Cl—Be—Cl
• C2H2:
Negative Charge Centers
• Three NCC
• Molecules with three charge centers will place them 120' from each other. Thus, giving a planar triangular shape to the distribution of electrons.
• If all NCC are bonded, the shape will also be planar triangular
• If one of the pairs is not bonded, it will result in a bent structure.
117'
Negative Charge Centers
• Four NCC
• Molecules with four charge centers will place them 109.5' from each other. Thus, giving a tetrahedral shape to the electron pairs
• Tetrahedral
• Trigonal pyramidal
• Bent or "V" shaped