Do Now:

• Define the following words in your notebook:– Element– Compound – Ion– Polyatomic ion

Element

• A substance that cannot be changed into simpler substances under normal laboratory conditions

Compound

• a substance that can be separated into simpler substances (elements or other compounds) only by chemical reactions (made of 2 or more elements)

Ion

• An atom or group of atoms that has a positive or negative charge– Cations ions with a POSITIVE CHARGE (because

they lost electrons)– Anions ions with a NEGATIVE CHARGE (because

they gained electrons)

Polyatomic Ion

• A covalently bounded group of atoms that behave as one whole unit and carry one single charge.

Metals VS NonmetalsMetals Nonmetals

Side of Periodic Table

When forming a compound

Charge

Groups with corresponding charge

Examples

Notes about Charge:

Ionic Compounds

• A compound composed of positive and negative ions

• How to recognize an ionic compound …• Cation and anion• Metal and nonmetal• + and -

Rules for Writing Formulas - Ionic Compounds

1. Write the symbol for cation first with charge2. Write the symbol for anion with charge3. Criss Cross charges4. Reduce (if necessary)

* Never leave + or – in a formula* Never use 1’s in a formula

Writing Ionic Formulas-Examples:

Steps:1. Write cation first with charge2. Write anion with charge3. Cris Cross charges4. Reduce (if necessary)

*Never leave + or – in a formula* Never use 1’s

1. Bromine and Calcium 2. Magnesium and Sulfur

TRY “Writing Ionic Formulas” #1-5

Lithium and Sulfur

Aluminum and oxygen

Magnesium and nitrogen

Strontium and sulfur

Potassium and phosphorous

Potassium and Oxygen

Transition Metals• Metals that have multiple charges• Charges are represented by roman numerals (in names

only)– Roman numerals are NOT used in formulas

Number Roman Numeral

1

2

3

4

5

6

7

8

9

10

EXCEPTIONS:(These only have one specific charge)

• Silver Ag1+

• Zinc Zn2+

• Cadmium Cd2+

MEMORIZE THESE!

Sn, Sb, Tl, Pb and Bi are also considered transition metals.

Steps:1. Write cation first with charge2. Write anion with charge3. Cris Cross charges4. Reduce (if necessary)

* Never leave + or – in a formula* Never use 1’s

1. Iron (II) and oxygen 2. Copper (I) and iodine

Writing Ionic Formulas(with transition metals)-

Examples:

TRY “Transition Metals and Non Metals” #1-3

Iron (III) and oxygen

Lead (IV) and nitrogen

Zinc and bromine

Nickel (I) and iodine

Steps:1. Write cation first with charge2. Write anion with charge3. Cris Cross charges4. Reduce (if necessary)

* Never leave + or – in a formula* Never use 1’s* Use ( ) when more than one p.i.

1. Magnesium nitrate 2. Sodium hydroxide

Writing Ionic Formulas(with polyatomics)-

Examples:

3. Lead (IV) sulfate

TRY “Writing Ionic Formulas with Polyatomics” #2-4

Work on HW!