Covalent bonding

• Science
• Upper Secondary (Key Stage 4)
• GCSE

Write the most
scientific sentence

Covalent bonding - small covalents

What are you going to learn?

In this lesson you will:

• check your understanding of the covalent bond
• prepare to practice drawing or completing covalent bonds
• be able to describe what is meant by the term 'small covalent molecule', giving examples of these.

Which of the following will not be involved in a covalent bond?

1. carbon
2. magnesium
3. hydrogen
4. fluorine

Why will magnesium
not be involved
in a covalent bond?

Which of the following elements will not form a covalent bond?

1. Helium
2. Boron
3. Sulfur
4. Iodine

Why do Noble gases
not form covalent bonds?

electron shared by H

electron shared by O

electrons not being shared by O

Which sub-atomic particles are shared in a covalent bond?

1. proton
2. inner shell electron
3. neutron
4. outer shell electron

What term decribes
what happens to
electrons in a covalent bond?

What group of the periodic table
is carbon in?

Group 1

Group 3

Group 4

Group 7

Group 0

How many more electrons does
carbon need to have a full outer shell?

1

3

4

7

0

How many electrons does
carbon share in covalent bonds?

1

3

4

7

0

What group is chlorine in?

1. 1
2. 7
3. 0
4. 2

The number of electrons a non-metal atom needs is the number it will...

1. loose
2. gain
3. transfer
4. share

How many electrons does
chlorine need for a full outer
shell?

1. 1
2. 7
3. 0
4. 2

How many electrons does
chlorine share?

1. 1
2. 7
3. 0
4. 2

Oxygen is in group 6
how many will it
share?

Nitrogen is in group 5
how many will it
share?

Oxygen has 6 outer shell electrons, it shares 2, how many electrons are not involved in a covalent bond?

1. 2
2. 4
3. 6
4. 8

Bromine is in group 7, it shares 1 electron with Hydrogen, how many electrons are not involved in a covalent bond?

1. 2
2. 4
3. 6
4. 8

How many of the hydrogen
atom electrons are not involved
in a covalent bond?

1. 0
2. 1
3. 2
4. 8

Small covalent molecules

• All the diatomic molecules
• The dioxides - CO2 , SO2 and NO2
• Methane - CH4
• Ammonia - NH3
• Water - H2O
• Nitrogen oxides

What is the maximum number of atoms in a small covalent?

1. 1
2. 2
3. 3
4. 4

Properties

• Almost all small covalent molecules are gases at room temperature (20-25oC)
• Almost all have negative melting and boiling points

What are the melting and
boiling points of small
covalent molecules like?

Which small covalent
molecule is NOT a gas
at room temperature?

Properties

No free electrons and therefore...

• Don't conduct thermal energy
• Don't conduct electricity

Special case

• Water is what we call a polar molecule.
• This means the diferent parts are slightly (not fully) charged
• The oxygen is slightly negative and the hydrogens slightly positive

Special case

• This means water molecules are attracted to each other
• The slightly negative oxygens are atracted to the slightly positive hydrogens in adjacent water molecules
• These are hydrogen bonds, a type of intermolecular force

Special case

• Other small covalents don't have these between the molecules
• Having these means a bit more thermal energy is needed to change water from a liquid to a gas
• Intermolecular means between molecules

What can small covalent
molecules NOT do?

Why can small covalent
molecules noy conduct?

What part of the water molecule is positive?

1. The hydrogen atoms
2. The oxygen atom
3. All of it
4. None of it

What part of the water molecule is slightly negative?

1. The hydrogen atoms
2. The oxygen atom
3. The hydrogen ions
4. The oxygen ion

What word describes what there is between water molecules that there aren't strong ones of between other small covalent molecules?

1. intramolecular bonds
2. intrinsic forces
3. intermolecular forces
4. intermolecular bonds

What is needed to
break intermolecular
forces?

Draw, snip and post a covalent bond diagram for H2

Draw, snip and post a covalent bond diagram for O2

Draw, snip and post a covalent bond diagram for CH4

Draw, snip and post a covalent bond diagram for N2

Draw, snip and post a covalent bond diagram for F2

Draw, snip and post a covalent bond diagram for CO2

Draw, snip and post a covalent bond diagram for H2O

How did that go?

😒🙁😐🙂😃