ch 4 molecular geometry

• electron geometry is the arrangement of electrons in an atom or molecule.
• group of electrons are single bonds, double bonds or triple bonds
• properties of molecular substances depend on structure of molecule including skeletal arrangement of atoms, bonding and shape of molecule
• bonding theory allows you to predict the shapes of molecules
• shapes of molecules affect their properties including physical states and their reactivity (drug or poison)
• taste depends on the interaction between food molecules and taste cells on your tongue
• lone pairs require more space than bonding pairs which leads to decreasing bond angles between bonding pair
• shape with two electrons around the central atom called linear
• molecular shape is the 3D arrangement of atoms defined by relative position in nuclei
• electron-electron repulsion arranges them as far apart as possible around central atom
• shape of molecule is determined by atoms on central atom
• ideal bond angles determined by electron geometry are tetrahedral, trigonal planar and linear angle
• real bond angle may deviate
• separation makes dipoles
• nonpolar shares electrons equally
• polar shares electrons unequally
• ionic transfers electrons
• molecular polarity depends on shape and bond polarity
• it is polar if it has 1/more polar bonds, and doesn't cancel individually
• symmetrical bonds are linear, trigonal planar and tetrahedral