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Covalent bonding
Learning objectives:
1. How can I draw covalent bonds?2. What are covalent bonds?
Starter - match these up!
• Carbon dioxide
• Water
• Chlorine
• Oxygen
• Methane
• Hydrogen
• Cl2
• O2
• CO2
• CH4
• H2
• H2O
Metals and Non-metals
Complete exam questions on the next slide.
(a) What is the formula of methane? ..........................................................................(1) (b) Choose a word from the box to answer the question.Which of the words best describes the methane particle shown in the diagram?
(1)
(c) Choose a word from the box to answer the question.What is the type of bonding shown in the diagram?
(1)
(Total 3 marks)
atom ion molecule
covalent ionic metallic
1. The diagram represents a particle of methane.
Study and take notesFind out what covalent bond is and how
to draw covalent bonds.
Cl
incomplete outer shells
The shared electrons join the atoms together. This is called a covalent bond.
The two non-metal atoms cannot form a bond by transferring electrons from one to another. Instead, they share electrons.
Each atom now has a full, stable outer shell.
Cl Cl
Cl
What is a covalent bond?
solid
line
Cl Cl–
–Cl Cl
A covalent bond is a shared pair of electrons.
Cl Cl
covalent bond
Cl
outer shell
dot and cross
diagram
Cl
Drawing covalent bonds
Rules of Covalent bonding
o Needs 2 or more NON-METAL ATOMS
o Electrons are SHARED to complete the shells
o The electron shells overlap.
Drawing Molymods
To do:
Next practice drawing covalent bonds for different molecules.
How many bonds?
What element
s?
1 2 3 4
O
Cl
H N C
• Hydrogen (H2)
• Chlorine (Cl2) • Hydrogen chloride (HCl)
•Water (H2O) •Methane (CH4) •Ammonia (NH3)
EXTENSION – draw O2 and CO2
Plenary – Ionic or Covalent• Using your periodic tables work out which
type of bonding will be shown in these compounds!
• Extension– draw an ionic compound and a covalent compounds
MgOCl2
NaCl
Li2O
HClCaCl2NH3
CH4
Br2
N2
H2O
O C
ClCl
Hint Sheet
O C
ClH
Hint Sheet
