Presentation on theme: " When non-metals gain electrons to become ions, the name of the ion changes its ending to “ide”. Fluorine fluoride Chlorine chloride Oxygen oxide."— Presentation transcript:
When non-metals gain electrons to become ions, the name of the ion changes its ending to “ide”. Fluorine fluoride Chlorine chloride Oxygen oxide
Metals tend to have 1, 2 or 3 electrons in their outer orbit and tend to lose these electrons when they combine with other elements to form positive ions.
Nonmetals tend to have 5, 6 or 7 electrons in their outer orbit. They all tend to gain electrons when they combine with metals to form compounds.
As mentioned in a previous class sodium (Na) and chlorine (Cl) are highly reactive with each other and combine to produce a fairly stable compound called NaCl (salt).
This compound is called an ionic compound because it made from positive and negative ions that transfer electrons from a metal to a non-metal.
Positive and negative ions are attracted to each other due to their opposite charges.
Sometimes in order to fill the valence shell some atoms have to combine with multiple atoms to become stable.
A chemical formula is a way of expressing information about the atoms that make up a particular chemical compound. The formula identifies each type of element by its chemical symbol and identifies the number of atoms of such element to be found in each molecule of that compound. Ex. Methane is CH 4
Magnesium chloride-MgCl 2 Aluminum fluoride-AlF 3 Glucose-C 6 H 12 O 6
Ionic Compounds dissolve in water and form solutions that conduct electricity because they are made up of charged ions. These ions separate from one another and are free to move around and carry an electrical current.
Molecular Compounds are formed when nonmetals combine with other nonmetals.
Review pages 188-189 and complete questions 1 and 2.
EXAMPLE 1- What is the formula for the ionic compound formed by calcium and fluorine? Step 1 Step 1 – Write the symbols of the elements with the metal first and non-metal second Ca F Step 2 Step 2 – Write the ion charge of each element Ca +2 F -1
Step 3 Step 3 – Determine how many of each you need to have an overall charge of zero. Ca +2 F -1 F -1 Step 4 Step 4 - Write the formula using subscripts, after the element, to indicate how many you used. Ca 1 F 2 CaF 2 ( 1 is not needed )
What is the formula for the ionic compound formed by aluminum and sulfur? Steps: 1) Al S 2) Al +3 S -2 3) Al +3 Al +3 S -2 S -2 S -2 4) Al 2 S 3
Al +3 S -2 Al 2 S 3 Watch out for lowest terms: Mg +2 O -2 Mg 2 O 2 = MgO - we can reduce to lowest terms
When naming an ionic compound we simply write the name of the metal first and non- metal second. We change the ending of the non-metal name so that it ends in “ide.”