LECTURE #5 Chapter 4 –Water Quality (Hwk#4- pp.112-113 2,4,6,10,14) Chemistry Review •Compound – A combination of Elements •Molecule – Smallest part of a Chemical compound •organic vs. inorganic- complex molecules of carbon in combinations with other elements is organic(i.e. organic pertains to living organisms and an exception would be CO2) •covalent vs. ionic bonding – shared electron atomic structure (covalent) vs. positive and negative charge attraction (ionic)[H20 .vs. NaCl]