Journal – Monday, September 23, 2013 Std: 1.d. Students know how to use the periodic table to find the electrons available for bonding. Independent Practice: Introduction to Ionic Bonding IP Stuff… Made Of WS Question: How many valence electrons do the following elements have: Indium Radium Xenon Phosphorus How do you know?

Today’s Objectives To review compounds and ions. To learn about ionic bonding. To practice determining the number of valence electrons, bonding structure, and the type of ion an element is likely to form.

Review: What is a compound? Pure substance that contains two or more elements.

Review: Law of Definite Proportions Definition: Pure compounds always contain the same elements in the same proportion by mass. Example: Water always contains two hydrogen atoms and one oxygen atom.

Valence Electrons The electrons in the outer shell are available for bonding. These are called the valence electrons. The goal of all atoms is to have the configuration of the nearest noble gas.

Chemical Bond A chemical bond is a force that holds atoms together in a compound.

Review: Ions An ion is an atom that is no longer neutral because it has gained or lost electrons. A positive ion has lost electrons (cation). A negative ion has gained electrons (anion).

Ionic Bonding – Transferring Electrons An ionic bond is an electrical attraction between positively and negatively charged ions in an ionic compound. Occurs between metal cations and nonmetal anions on the periodic table.

Chemical Formulas A chemical formula contains atomic symbols and subscripts to show the elements and the number of atoms of each element that can combine to form a compound. It’s basically an ingredient list: telling you which elements are in the compound and how much of each.

Chemical Formulas A formula unit is the lowest whole number ratio of ions in an ionic compound. Example: For sodium chloride, the lowest-whole number ratio of ions is 1:1 (one Na+ to each Cl-).

Properties of Ionic Compounds These compounds are also called salts. They are usually solid at room temperature. They are brittle, which means they easily break apart. Many ionic compounds dissolve in water. Good conductors of electricity. Usually have high melting points.

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