Ionic bonding , chemical bonding

IONIC BONDING

Why do atoms form bonds ?


What is the chemical equation of this reaction ?

NaCl
Atoms of sodium and chlorine have bonded to form a compound. How is the bond in this
compound formed?


1. THE FORMATION OF ION, CATION AND ANION




Why do atoms form bonds?

•

Atoms bond with each other in order to gain a stable arrangement of outershell electrons, like the atoms of Group 0.

•

In other words, they bond in order to gain 8 electrons in their outer shell (or 2,
if they have only one shell- Hydrogen).


What is an ion ?

II. THE FORMATION OF IONIC BONDS

An ionic bond is the bond formed by the attraction between oppositely charged ion


Common Monoatomic Ions

In general:
Metal atoms and hydrogen lose e- and form cations.
Nonmetal atoms gain e- and form anions.


+ Metal elements which belong to Group IA, IIA, IIIA have 1, 2 or 3 elctrons in outermost shell
and they can lose 1, 2, 3 electrons so their positive charge are 1+, 2+, 3+.

+ Non-metal elements which belong to group VIA, VIIA have 6 or 7 electron in outer shell and
they can gain 2 or 1 electrons so their negative charge are 2-, 1-.


III. Names of Monoatomic Ions - Cations

•

Cations formed by a metal have the same name as the metal.
+
K
Ca
Al

•

potassium ion
2+

3+

calcium ion
aluminum ion

If a metal forms more than one cation, use Roman numerals in ( ) after the name of the metal to show its
charge.

2+
Fe

iron (II) ion

3+
Fe

iron (III) ion

Cu
Cu

+
2+

copper (I) ion

copper (II) ion


IV. Names of Monoatomic Ions - Anions



Monoatomic anions are named by:

 dropping the ending of the element’s name
 adding “ide”
N
3N

nitrogen

nitride

2O

O

oxygen

oxide


mXOn

Naming Oxyanions



Many of the polyatomic anions are oxyanions.

 polyatomic anions containing one or more oxygens attached to a
central atom



To name an oxyanion, drop the ending of the central atom name and
add:

 “ate”

most common oxyanion
of the element

 “ite”
NO3
NO2

CO3

2-

nitrate

1 less oxygen
2SO4

sulfate

2SO3

nitrite

carbonate
PO

PO4
3-

3-

sulfite

phosphate

phosphite


Writing Formulas for Ionic Compounds
Example: Write the correct formula for the following ionic compounds.

 Zinc bromide
 Aluminum carbonate
 Iron (II) phosphate
 Tin (IV) sulfate
 Magnesium hydroxide

Writing Formulas for Ionic Compounds
Example: Write the correct formula for the following ionic compounds.

 Sodium bicarbonate
 Ammonium sulfate
 Potassium phosphite
 Sodium hypochlorite
 Copper (I) oxide


Naming Ionic Compounds
Example: Name the following ionic compounds.



Na2SO4



FeCl3



(NH4)3PO4



KCl



CuCO3



MgSO4