Aim How do chemists write and interpret chemical

Aim: How do chemists write and interpret chemical formulas? How are elements named? • IUPAC- International Union of Pure and Applied Chemists • Formulas use chemical symbols and numbers to show both qualitative and quantitative information.

Aim: How do chemists write and interpret chemical formulas? Distinguish between empirical and molecular formulas: • Empirical- simplest integer ratio; Ionic formulas indicate an array of ions in a compound, not a discrete molecule. • Molecular- ACTUAL ratio of atoms in a molecule.

Aim: How do chemists write and interpret chemical formulas? How to name binary ionic compounds? • Write the name of the cation (positive ion) followed by the name of the anion (negative ion) with suffix “IDE. ” This is qualitative information. • Roman numerals represent the CHARGE ON THE CATION. Subscripts denote the number of atoms or ions. This is quantitative information.

Aim: How do chemists write and interpret chemical formulas? Why does one have to enclose polyatomic ions in parentheses when writing formulas? Polyatomic Ion- group of atoms covalently bonded together possessing a charge. How to name covalent compounds? • Use prefixes to note the number of each type of atom: mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca-

Aim: How do chemists write and interpret chemical formulas? How to draw particle diagrams representing chemical formulas? • Choose a different color for each element. • Make sure circles representing atoms are touching within a given compound. Particle Diagram Examples