Covalent Bonding and Molecules

1. Covalent Bonding and Molecules When compounds form between elements with similar properties, electrons are not transferred from one element to another but instead are sharedin order to give each atom a noble gas configuration. Lewis theory depicts bond formation in H2 as H∙ + ∙H → H:H This type of arrangement, where two atoms share a pair of electrons, is known as covalent bonding, and the shared pair of electrons constitutes a covalent bond.

2. Covalent Bonding and Molecules Diatomic molecules contain two atoms and may be either heteronuclear or homonuclear. Polyatomic molecules contain more than two atoms.

3. Covalent Bonding and Molecules An empirical formulas, gives the whole-number simplest ratio of elements in a compound. Amolecular formulagives the actual number of atoms of each element in a molecule of a compound. The formulas for ionic compounds are empirical – they can be referred as unit formula or formula unit

4. Representing Compounds:Molecular Models • Modelsshow the 3-dimensional structure along with all the other information given in the structural formula • A structuralformulauses lines to represent covalent bonds and shows how atoms in a molecule are connected or b • Ball-and-stick modelsuse balls to represent the atoms and sticks to represent the attachments between them • Space-filling modelsuse interconnected spheres to show the electron clouds of atoms connecting together

5. The ionic compound that has two aluminum ions for every three oxide ions arabinose, C5H10O5 pyrimidine ethylene glycol Find the empirical formula for each of the following Al2O3 CH2O C2H2N CH3O

6. Covalent Bonding and Molecules