Ionic bondsPg. 51

An ion is an element that has gained or lost electrons

Oxidation numbers are used to show the charge of an ion.

A positive ion is called a cation A negative ion is called an anion

Ions

Write the element symbol first As a superscript, write the oxidation number

Ex. Ba2+ or Ba+2

Writing ions

Force that holds oppositely charged ions together is called an ionic bond

Between a metal and a nonmetal Electrons are lost or gained High melting and boiling points Can dissolve in water to produce

electrolytes (produces an electric current)

Example: NaCl

Ionic Bonds

Lowest ratio called a formula unit First write the ions with their oxidation numbers The charges on each elements switch and become

the subscripts (tells the amount of that atom) on the other element

Take just the numbers, NOT THE CHARGES Simplify The metal goes first then write the nonmetal. Examples:

◦ Na and Cl◦ Mg and F◦ K and P◦ Be and O

Writing Ionic compound formulas

◦ Na and Cl◦ Mg and F◦ K and P◦ Be and O

Lewis Dot diagrams

The cation is written as normal The anion drops the last part of the element

and add –ide Example: Sodium + Chlorine = Sodium

Chloride

Naming Ionic compounds

Complete the ionic bonding side of the worksheet.

Your turn

Write ionic bonds for the following:◦ Rubidium and Phosphorus◦ Gallium and oxygen

Use a Lewis Dot diagram to show how Aluminum and Sulfur would bond

What is an ionic bond between? What are two characteristics of an

ionic bond?

Daily ScienceNovember 3

Ions made up of more than one element Charge applies to the entire ion Written in parenthesis in ionic formulas Ex. Mg(OH)2

Polyatomic ions

Ion name Ion Formula

Ammonium NH4+

Nitrite NO2-1

Nitrate NO3-1

Hydroxide OH-1

Cyanide CN-1

Hypochlorite ClO-1

Chlorite ClO2-1

Chlorate ClO3-1

Carbonate CO3-2

Sulfite SO3-2

Sulfate SO4-2

Phosphate PO4-3

Sodium Phosphate

Calcium Chlorite

K2CO3

Poly atomic examples

Transition metals can have multiple charges When writing the name, the charge of the

transition metal must go in parenthesis using Roman numerals

Reverse the subscripts to find the charge◦ Check the charge on the nonmetal first

Ag+1, Zn+2, Cd+2 only have one common charge

Ex. Iron (III) oxide◦ Cu3P2

◦ MnO

Ionic formulas with transition metals