5.3-Compound Names and Formulas I can: -use the period table to determine period charge in Groups 1, 2, and 17, including hydrogen and oxygen -identify a compound using conventional naming systems that include Greek prefixes where appropriate (Prefixes limited to represent values from one to 10) -identify the formula for a covalent or ionic substance

Naming Ionic Compounds Formed by cations-anions. Both ions are included in name. Naming of cations include the elements of which they are composed. Sodium loses an electron= Na+ Calcium loses two electrons= Ca2+ Aluminum loses three electrons= Al3+ Group 1 ions have 1+ charge, while group 2 has 2+ charge

Naming Ionic Compounds, cont. Names of anions are altered names of elements. Same group will have same charge “ide” is placed as suffix NaF=sodium fluoride

Same cation names must show their charge FeO v. Fe2O3 Both named iron oxide See the problem? Transition metals can form several cations with different charges. Some cation name must be followed by Roman numeral in parentheses. Fe2O3 = Fe3+, Iron(III) oxide. now where did the Fe3+ come from?

Determining the charge of a transition metal cation. Total charge must be 0! https://www.youtube.com/watch?v=_w6-4fRQt1Y

Writing Formulas for Ionic Compounds What is the formula for Aluminum Fluoride? AlF3

Naming Covalent Compounds SiO2 (silicon dioxide) and CO2 (Carbon Dioxide) Where are they on the periodic table? Numerical (#’s) prefixes are used to name covalent compounds of two elements Tells how many atoms of each element 1 atom in first element does not get prefix Whichever element is further right on periodic table is named second and ends in “ide.” In other words, start with one that is more metal like. BF3 Boron trifluoride N204 Dinitrogen Tetroxide CO?

Chemical Formulas for Covalent Compounds Mass of each element in compounds must be measured first. Empirical Formula (simplest): Tells smallest whole-number ratio of atoms that are in compound. (reduced to ratio) H2O= 2:1 ratio Problem: compounds can have same empirical formula, but be very different.

Molecular formulas are determined from empirical formulas. Each compound has its own Moleculelar formula: chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of atoms. (actual number) Look at examples on previous slide.

practice http://www.sciencegeek.net/Chemistry/taters/Unit3BinaryNomencla ture.htm