Chapter 12.2. Standards: GLE 0807.9.2 GLE 0807.9.4 GLE 0807.9.6.
-
Upload
rosalind-quinn -
Category
Documents
-
view
227 -
download
3
Transcript of 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.
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?
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
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.