Ionic and Covalent Compounds Mrs. Taylor

Millions of compounds form from the elements of the periodic table Naming is essential in chemistry

Two Types of Compounds Ionic Covalent

Ionic Compounds Are formed between metals and nonmetals

CO2 NH3 H2O O2 N2 H2 Covalent Compounds Are formed between 2 or more nonmetals Compound may be formed between two different nonmetals Compound may be formed between two of the same nonmetals. CO2 NH3 H2O O2 N2 H2

Exit Ticket 1. Where are metals located? Right or left? 2. Which element is the exception? 3. Ionic Compounds are formed between __________ and ___________. 4. Covalent Compounds are formed between ___________________. 5. Give an example of an ionic bond. 6. Give an example of a covalent bond.

COMPOUND FORMATION Elements want to form bonds so that they can achieve eight electrons in their outer most energy level. THIS IS AN OCTET! The electrons in the outermost level are called valence electrons

Valence Electrons We can determine the number of valence electrons an element has by the group of the periodic table that the element is in.

HELIUM is the only exception HELIUM is the only exception! Helium is has 2 electrons even though it is in the last group!

IONIC COMPOUND FORMATION When an atom of a nonmetal takes one or more electron from an atom of a metal so both atoms end up with eight valence electrons In other words, a nonmetal is gaining an electrons (anion) and a metal is losing electrons (cation). We can think of ionic bonds as an attraction between positive and negative particles.

Determining Charges of the Periodic Table (WRITE THEM ON YOUR PT)

Writing Formulas for Ionic Compounds: (No transition metals) Made of metals and nonmetals Metal always goes first, nonmetal goes second Name ends in –ide if no polyatomic ion present Net ionic charge must = zero If ionic charges are equal in magnitude but opposite in sign, they cancel If there is a polyatomic ion, put parenthesis around it

Polyatomic Ion Covalently bonded group of nonmetal elements with a charge. Ex: CO32- NH4+

Practice Calcium nitride Sodium oxide Lithium Chloride Magnesium sulfide  Lithium carbonate Magnesium sulfate Calcium phosphate Aluminum acetate

C. Naming Ionic Compounds: Those that do NOT contain a transition metal   Name ends in –ide unless there is a polyatomic ion present Just write the name of the ions you see

Practice NaBr CaCl2 Mg3(PO4)2 Li2SO4  

A. Writing Formulas for Molecular Compounds Prefixes tell you the number of each type of atom Do NOT criss cross any numbers!

Practice Dichlorine tetrafluoride Nitrogen triodide Trisulfur hexafluoride  Carbon monoxide Tetrabromine hexanitride  

B. Naming Molecular Compounds If there is a single atom of the first element, omit ­mono- Name ends in –ide

Practice P2O5 S2Cl6 CO2 Cl2O CCl4

S U P E R 7 Diatomic Molecules Elements that do not exist alone. There are seven. (N2, O2, F2, Cl2, Br2, I2 and H2)

Exceptions to the Rules H2O  Water NH3  Ammonia