Naming Compounds 10/01/2015

Warm Up

How does Lithium and Phosphorous combine to form an ionic compound?

Schedule10.01.2015

Warm Up

Naming Ionic Compounds

Covalent Bonds - Fruit Loop Activity

Work Time

Homework: Nomenclature of Ionic and Covalent Compounds Worksheet-

Due Friday October 2nd Vocabulary- Due October 2nd Test/Lab Corrections- Due October 2nd Vocabulary Quiz Tomorrow!

What does a subscript and a superscript tell us ?

Subscripts: How many atoms are in a compound Example: S2

Superscripts: Tell us the charge on an elementExample: S2+

How do we Write a Chemical Formula for an ionic compound?

1) We need to look at the charges for the two elements combining

2) Look at Lithium and Fluorine. What are their charges?

Write these ions with their charges. Then use the Crossing Over Rule

Li1

+

Cl1-

Li1

Cl1

New Compound: LiCl

The charges cancel each other out if they

are similar

Examples

How do we name Ionic Compounds?

1. Write the name of the metal first Example: Lithium

2. Follow it with the name of the nonmetal

Example: Lithium Chlorine

3. Add the suffix "ide" to the end of the nonmetal

Example: Lithium Chloride These are binary compounds because they only contain two elements

Polyatomic Ions and how we name them

Not all ionic compounds are binary compounds.  Some ionic compounds are form by using both ionic bonding and covalent bonding. 

The resulting ion contains a charge, because the total number of electrons from the set of atoms cannot produce a stable structure.

Some Examples of Polyatomic Ions:

Covalent Bonding and how we name these bonds

A Covalent Bond is when two elements share electrons

The Lewis structure of a fluorine atom shows that each fluorine atom has seven valence electrons.

Make this Fluorine atom with your Fruit Loops

Covalent Bond

A fluorine atom needs one more electron to be happy.

If a fluorine atom shares one of its electrons with another fluorine atom, the valence shells of both atoms become filled. The two shared electrons form a single bond between the atoms.

 A line can be used to represent the shared electron pair.

Now Write the Chemical Formula for this Covalent Bond on this slide

F

Now try Hydrogen + Oxygen

Fruit Loop Activity

Pass out Bags with Fruit Loops and Letters

Pass out Worksheet

We will make these Covalent Bonds as a class – follow my directions on the Document Camera

Naming Covalent Bonds or Molecular Compounds

 If a chemical formula is given, the first element in the formula is named first. 

To describe the number of atoms of each element in a molecule, the chemical nomenclature uses Greek prefixes.

Example

H2S

Name: dihydrogen monosulfide

Empirical Formula vs. Molecular Formula

The formula of a compound expressed as the smallest possible whole-number ratio of subscripts of the elements in the formula

For example, CH3COOH has two carbons, four hydrogens and two oxygens. So we could write the formula like this: C2H4O2 and so it reduces to CH2O.