Chemical Bonding Revision Notes

1. Bartley Secondary School
Science Department
Name: ______________________ Date: _____________
Class: ______________
Revision notes on Chemical Bonding
Atoms lose or gain electrons to achieve a stable octet structure. (8 valence
electrons)
Metal atoms  give away electrons positive ions (cations)
Non-metals gain electrons  negative ions (anions).
Ionic bonding
·Occurs when a metal atom combines with a non-metal atom
·Formed by TRANSFER OF ELECTRONS FROM A METAL ATOM TO A
NON-METAL ATOM
·Occurs between ions of opposite charges attracting each other
Transfer of electrons
Covalent bonding
·Occurs mostly between non-metals
·Formed by SHARING OF ELECTRONS between two atoms.
Sharing of electrons
Prepared by Miss Syikin, 2007.

2. Bartley Secondary School
Science Department
Differences between ionic and covalent compounds.
Property Ionic compound Covalent compound
Electrical conductivityConducts electricity when
molten or dissolved in
water
Does not conduct
electricity in any state
Melting and boiling
points
High Low
Solubility in water Mostly soluble Mostly insoluble
Solubility in organic
solvents
Mostly insoluble Mostly soluble
List of common cations and anions
Cations (positive ions) Anions (negative ions)
Ammonium ion NH4
+
Chloride ion Cl
-
Aluminium ion Al
3+
Fluoride ion F
-
Calcium ion Ca
2+
Bromide ion Br
-
Copper (I) ion Cu
+
Iodide ion I
-
Copper (II) ion Cu
2+
Nitrate NO3
2-
Hydrogen ion H
+
Sulphate SO4
2-
Iron (II) ion Fe
2+
Oxide O
2-
Iron (III) ion Fe
3+
Hydroxide OH
-
Magnesium ion Mg
2+
Sodium ion Na
+
Potassium ion K
+
Zinc ion Zn
2+
Prepared by Miss Syikin, 2007.

3. Bartley Secondary School
Science Department
Name: ______________________ Date: _____________
Class: ______________
Revision Practice
1.The electronic structure of sodium and chloride atoms are respectively
2.8.1 and 2.8.7.
(a)What is the valency of chlorine in sodium chloride?
………………………………………………………………………………………
(b)(i) Draw the electron arrangement of the particles formed when an atom of
sodium reacts with an atom of chloride.
(ii) What is the name given to this type or bonding?
………………………………………………………………………………………
(iii) How does this bonding help to explain the high melting point of sodium
chloride?
………………………………………………………………………………………
………………………………………………………………………………………
2.The electronic configuration of a sulphur atom is 2.8.6.
(a)Write in the same way, the electronic configuration of the atoms of carbon
and oxygen.
Carbon ……………………………….. oxygen ……………………………
Prepared by Miss Syikin, 2007.

4. Bartley Secondary School
Science Department
(b)Draw a diagram showing the electronic arrangement in a molecule of
carbon dioxide.
3.Three properties of five substances are shown in the table below. Each
substance is represented by a letter.
SubstanceMelting point /°C Electrical conductivity
Solid liquid
V 1083 Good Good
W 870 Nil Good
X -23 Nil Nil
Y 2027 Nil Nil
Z 98 Good Good
State the letter of a substance which is:
(a)a solid at 1100°C ………………
(b)ionically bonded ………………
(c)most likely to be soluble in water ………………
(d)composed of small, cavalently-bonded molecules ………………
4.Complete the following table;
Formula Type of bond
(a)sodium chloride
(b)carbon monoxide
(c)water
(d)methane
(e)copper (II) oxide
Prepared by Miss Syikin, 2007.