The Covalent Bond and Molecular Compounds Chemistry Mrs. Coyle
Types of Bonds • Ionic • Metallic • Covalent
The Covalent Bond • The bond in which atoms are held together by their mutual electrical attraction for shared electrons. Fluorine
Movie Clip • http://www.youtube.com/watch?v=Kj3o0XvhVqQ&NR=1
The Covalent Bond • A single covalent bond is made up of two electrons. • The covalent bond is represented using a straight line. F — F F F
Molecule • A neutral group of atoms joined together by covalent bonds.
Diatomic Molecules • Molecules made up of two atoms. • There are 7 diatomic molecules. • H2, N2, O2, F2, Cl2, Br2, I2
Hydrogen H· + ·H H:H Hydrogen Hydrogen Hydrogen Atom Atom molecule • The hydrogen molecule has a single covalent bond. • The electronegativity of each hydrogenatom is the same, so the electrons are shared. Shared electron pair
Molecular Compounds • Compounds comprised of molecules.
Molecular Formula • A molecular formula is a chemical formula that is used for molecular compounds. • It shows the types and number of atoms in a molecule. • Note that ionic compounds used the chemical formula called the formula unit. • A molecular formula does not give information about the molecules structure.
Structural Formula • Structural formulas show the arrangement of atoms in a molecule. • In a structural formula, the electron pair is represented by a line • Example: H-H (single bond: one pair of electrons)
Space Filling Model Methane CH4
Ball and Stick Models Ethane C2H6
The Ammonia Molecule . NH3