IONIC BONDING
2014-2015
Science 8
TERMS
TO
KNOW
Ion: an atom or atoms with an electric charge
 Polyatomic ion: an ion made of more than one
atom
 Ionic bond: chemical bond between two
oppositely-charged ions
 Compound: the product of the bond between the
ions
 Subscript: a number in a chemical formula that
tells the ratio of elements in an ionic compound.
 Chemical formula: the symbols and subscripts
showing the elements in a given compound.

IONS

Atoms without full valence shells can gain or lose electrons.


Cations are atoms that have lost electrons (lost negative energy) and are
therefore positive ions.
Anions are atoms that have gained electrons (gained negative energy) and
are therefore negative ions.
IONS
Consider Lithium and Bromine and answer the following questions.
 1) Circle. Lithium is a (metal/nonmetal) and Bromine is a
(metal/nonmetal).
 2) Lithium has
valence electrons. Bromine has
valence electrons.
 3) How many valence electrons make an atom feel “full”?
 4) It takes a lot of energy to hold onto valence electrons in a nearempty shell. Which element is more likely to lose their valence
electron?
 5) What type of ion will Lithium become?

IONS
Consider Lithium and Bromine and answer the following questions.
 1) Circle. Lithium is a (metal/nonmetal) and Bromine is a
(metal/nonmetal).
 2) Lithium has 1 valence electrons. Bromine has 7 valence electrons.
 3) How many valence electrons make an atom feel “full”? 8
 4) It takes a lot of energy to hold onto valence electrons in a nearempty shell. Which element is more likely to lose their valence
electron?
 5) What type of ion will Lithium become? Positive (+1) cation

IONS
Because metals do not have many valence electrons and their shells
are relatively empty, they will tend to lose their electrons and become
cations.
 Nonmetals, on the other hand, tend to have almost full valance shells,
and therefore will gain electrons and become anions.
 Cations and anions are oppositely charged, and because of that, they
are attracted to each other. This is a chemical bond called an ionic
bond, because it is a bond between two ions.

IONIC BOND PROPERTIES

Ionic compounds are generally:

Hard, brittle crystals that have high melting points, conduct
electricity and are dissolvable in water.
IONIC COMPOUNDS – FORMULAS AND NAMES
Compounds are often written by their chemical formula, or the
symbols that also show the ratio of atoms needed to make the
compound.
 To find the formula, you need to find the charge of the ion, then
balance them.

IONIC COMPOUNDS – FORMULAS AND NAMES

Practice: Find the ionic charges, then balance.
A) Na
 B) Mg
 C) Rb

O
Cl
N
IONIC COMPOUNDS – FORMULAS AND NAMES

Practice: Find the ionic charges, then balance.
A) Na
 B) Mg
 C) Rb

O
Cl
N
Na 0
MgCl
Rb N
IONIC COMPOUNDS – FORMULAS AND NAMES
To write the name of an ionic compound, you write the positive ion
(metal) first, and then the negative ion.
 If the negative ion is a sign element, and not a polyatomic ion (an ion
with many atoms), then you change the suffix to –ide.
 It does not matter how many atoms you have of each.
 Write the names of the three examples below:

Na20
 MgCl2
 Rb3N

IONIC COMPOUNDS – FORMULAS AND NAMES
To write the name of an ionic compound, you write the positive ion
(metal) first, and then the negative ion.
 If the negative ion is a sign element, and not a polyatomic ion (an ion
with many atoms), then you change the suffix to –ide.
 It does not matter how many atoms you have of each.
 Write the names of the three examples below:

Na20 sodium oxide
 MgCl2 magnesium chloride
 Rb3N rubidium nitride

REVIEW QUESTIONS
Review Questions:
 Ionic compounds are formed mostly between:

When an atom loses a valence electron, it becomes a(n)
.
 In an ionic compound, the total positive charges of all the
positive ions
the total negative charge of all
the negative ions.

REVIEW QUESTIONS
Review Questions:
 Ionic compounds are formed mostly between: metals
and nonmetals
 When an atom loses a valence electron, it becomes a(n)
anion.
 In an ionic compound, the total positive charges of all the
positive ions equals the total negative charge of all the
negative ions.

Ionic Bonding
Terms to know:
 Ion: an atom or
with an
charge
 Polyatomic ion: an ion made of more than
atom
 Ionic bond: chemical bond between two
charged ions
 Compound: the
of the bond between the ions
 Subscript: a number in a chemical formula that tells
the
of elements in an ionic compound.
 Chemical formula: the symbols and
showing the elements in a given compound.
GLUE THIS SIDE DOWN IN YOUR NOTEBOOK
Page #


A) Na O

B) Mg Cl

C) Rb N
To write the name of an ionic compound, you write
(metal) first, and then the negative
.
the
 If the negative ion is a sign element, and not a
many atoms), then you change the suffix to
 It does
not matter
atoms you
 Write the names of the three examples


Na20

MgCl2

Rb3N
(an ion with
.
have of each.
below:
Review Questions:
1) Ionic compounds are formed mostly between:

2) When an atom loses a valence electron, it becomes a(n)
.
3) In an ionic compound, the total positive charges of all the positive ions
the total negative charge of all the negative ions.