Chemical Formulas-Ionic Chapter 6 Sections 1-4

Classifying Elements-Metals Are located to the left side of the staircase line on the periodic table Display the following properties Malleability Luster Ductility Conduct heat Conduct electricity Tend to lose electrons to form positive

Classifying Elements-Nonmetals Are located to the right of the staircase line on the periodic table Display the following properties Soft and brittle Have an odor Do not Conduct heat or electricity Many are gases at room temperature Tend to GAIN electrons and form negative ions

Classifying Elements-Metalloids Are the elements directly touching the staircase line of the periodic table. Exhibit both properties of metals and nonmetals May form either positive or negative ions Generally, the elements at the top of the periodic table make positive ions and those at the bottom form negative ions

Periodic Table colored to show metals, nonmetals, and metalloids http://hyperphysics.phy-astr.gsu.edu/hbase/pertab/pertab.html

Ions An ion is an atom with a charge-either positive or negative Positive ions are called CATIONS. They have lost electrons. Negative ions are ANIONS. They have gained electrons. A polyatomic ion has more than one atom attached with the charge.

Oxidation Number The charge and the number that represents the number of electrons lost or gained. This is a cation with 1 missing electron. This is an anion with 1 extra electron

Binary vs. Ternary The prefix “bi” means two. Binary compounds have only TWO elements in their formula. Ternary compounds have three elements in their chemical formula.

Name: Calcium Phosphate Formula A Formula is a shorthand way to represent a chemical compound using symbols and numbers. Phosphate ion made up of 1 phosphorous and 4 oxygen atoms Name: Calcium Phosphate Ca3(PO4)2 2 Phosphate ions Calcium symbol A Subscript: 3 Calcium ions

In the Real World Follow the link to learn the formulas for our gemstones. http://pubs.usgs.gov/gip/gemstones/formulas.html

Formulas Easily written The sum of the positive charges and the negative charges must add up to be zero! Subscripts will be used to multiply charges if needed You will sometimes use parentheses with polyatomic ions. The “criss-cross” method will help check your work

Criss-Cross Method Mg3P2

Naming Ionic Compounds The positive ion name is the name of its element The negative portion will have a special ending Single atom ion will end in -ide Polyatomic ions end in either -ate -ite

Roman Numerals/Stock System Many of the transition metals are troublesome because they can have more than one oxidation number Iron can be Fe+3 or Fe+2 Copper might be Cu+1 or Cu+2 We indicate which form of the metal we used by a roman numeral: Iron(III) is Fe? Cu+2 is Copper(?)

Practice This unit absolutely requires that you practice using the naming rules! That’s why there are several labs and worksheets This item also appears on the TAKS test, so I don’t want you to just learn it for the test and forget the information!