Ionic Bonds

Chapter 12.2

Standards:

• GLE 0807.9.2• GLE 0807.9.4• GLE 0807.9.6

Key concepts:

• Explain how ionic bonds form.• Describe how positive ions form.• Describe how negative ions form.• Explain why ionic compounds are neutral.

Key Vocabulary:

• Ion• Ionic bond

Ionic Bond:

• Ionic bonds form when electrons are transferred from one element to another– Ionic bonds occur between metals

and non-metals• Ionic bonds have the following

properties:– High melting and boiling points– Can be brittle in solid state– Think salt

What is a compound?

What is a bond?

Completely the opposite of ionic bonds

Ionic Bond:

• Ionic bonds:– Atoms are neutral because protons

and electrons are equal– Transfer of electrons change the

number of electrons for each element– Create ions: charged particles that

are formed when atoms gain or lose electrons• Atoms must be close to each other for

them to gain or lose

– Created compounds are NEUTRAL

What is a compound?

What is a bond?

What is an ion?

Picture time! For Metals…

Picture time! For Non-metals…

Lewis Dot Structures

• Metal must become a cation by giving up an electron.

• Nonmetal must receive an electron and become an anion.

• The ionic bond is an electrostatic attraction between the positive and negative ion

ClNaSodium atom Chlorine atom

Na+

Sodium chloride

Cl -

Lewis Dot Structures

• Ion – an atom or group of atoms with a charge ( + or - ).– Cation – positive ion formed from a metal giving up 1-3

electrons– Anion – negative ion formed from a nonmetal gaining

1-3 electrons.

Mg2+

Cl

Cl-

Cl

Cl

MgCl2Mg

Lewis Dot Structures

• Oxidation Number - a “+” or “-” number given to an atom or group of atoms that represent the number of electrons that have been given (+) or received (-).

X X X X X X X X

+1 +2 +3 -3 -2 -1

0

-4

+ He

Picture time! For Metals…

Picture time! For Non-metals…

Ionic Bond:

• Energy Talk:– When Metals lose electrons, it

requires energy• Always metals• Will always be POSITIVE ions

– When Non-metals gain electrons, it gives off energy• Non-Metals always will be NEGATIVE• When written, end in -ide

What is a compound?

What is an ion?

Pearls of Wisdom:

• An ionic bond is a bond that forms when electrons are transferred from one atom to another. During ionic bonding, the atoms become oppositely charged ions.

• Ionic bonding usually occurs between atoms of metals and atoms of nonmetals.

• Energy is needed to remove electrons from metal atoms. Energy is released when most nonmetal atoms gain electrons.

Homework:

• Questions from page 317– Number 3-9