Different Terms Molecular Substances belong to two groups Molecular elements Two of the same non-metals O 2 Molecular Compounds Two different non-metals CO 2.
Molecular Elements Due to their reactive nature, some elements will never be found as single atoms. H 2, N 2, O 2, F 2, C l 2, Br 2, I 2 These can be explained with Lewis models S 8 and P 4. These are not easily explained via models
Molecular Elements (cont.) Draw Lewis Models for F 2, H 2 and for N 2. OO O O O +
Structural Diagrams To convert a Lewis Model into a Structural Diagram, replace each covalent bond (pair of shared electrons) with a dash. Draw Structural Models for F 2, H 2 and for N 2. OO O=O
Types of Bonds Covalent bonds can be Single ( 1 pair of shared electrons ) Double ( 2 pair of shared electrons ) Triple ( 3 pair of shared electrons ) More bonds are stronger bonds
Determination of Ionic Formula’s Given a metal & non-metal such as calcium and nitrogen you can “figure out” the product Ca 3 N 2 by “swapping charges” and simplest whole number ratios.
Determination of Molecular Formula Given two non-metals you can not “figure out” the product. You either memorize or use the name.
Drawing Molecular Structures Additional rules are needed to draw the more complex molecular structures. Draw a molecular structure for C 2 H 6 Draw the electron dot diagram of the atom that has the highest bonding capacity. Form shared pairs of bonding electrons with the remaining atoms.
If any bonding electrons remain on adjacent atoms, form a double or triple bond. In the finished electron dot diagram, all atoms (except hydrogen) should contain a stable octet. Draw a structural diagram of the molecule.