The Atom, Ions & Ionic Bonding

The Atom The smallest building block of matter. Contains three sub-atomic particles: 1. Proton (p + ): Positively charged, inside the nucleus. 2. Neutron (n o ): No charge, inside the nucleus. 3. Electron (e - ): Negatively charged, in shells around the nucleus. Valence Shell: The outermost shell in an atom. 3 p + 4 n 0 Bohr-Rutherford Diagram of Lithium

The Atom & The Periodic Table The periodic table is arranged into groups (columns) and periods (rows). It has three major classifications: metals, non- metals & metalloids. The staircase line runs through the metalloids. The group number of an element corresponds to the number of electrons in its valence shell.

Ions Atoms that have an unequal amount of protons and electrons are called ions. Two types: 1. Cations (positive ions): # of electrons < # of protons 2. Anions (negative ions): # of electrons > # of protons Metals form cations, Non-Metals form anions.

Ionic Bonding Combination of metal(s) and non-metal(s) elements. Involves a transferring of electrons: Metals lose electron(s) to gain a full octet. Non-Metals gain electron(s) to gain a full octet. Name ends in “-ide”. The ions are then held together electrostatically. Law of electric charges: Like charges repel Unlike charges attract

Example #1 For each metal / non-metal pair below i) Draw the Lewis dot diagram for the resulting compound ii) Write the chemical formula iii) Name the compound produced a) Ca and Ob) Na and Hc) Li and S Ca O Na H Li S Ca Li xx x x xx xx x x xx O CaO Calcium Oxide x Na H x NaH Sodium Hydride xx x x x x Li S xx x x x x Li 2 S Lithium Sulphide

Example #2 On your own… a) K and O b) Al and S c) Ba and N

Homework Worksheet: Naming Binary Ionic Compounds P.191 #5 & 6; P.195 #3 & 4