bondings

Question 1

Ionic bonding

Answer 1

Ions are charged particles.

Ionic bonding occurs between a metal and a non-metal.

In ionic bonding the positive and negative ions are held
together by strong electrostatic forces of attraction.

Question 2

Metallic bonding

Answer 2

Metallic bonding occurs between metals.

There are strong electrostatic forces of attraction between the cations ond the sea of delocalised electrons.

Delocalised electrons are free to move.

Question 3

Covalent bonding

Answer 3

A covalent bond is a shared pair of electrons.

Covalent bonding occurs between non-metal atoms.

Question 4

Giant covalent substances

Answer 4

made up of millions and millions of atoms which are all bonded together with a network of covalent bonds.

Question 5

structure of Giant covalent substances

Answer 5

Diamond – Made up of carbon atoms. All carbon atoms bonded to 4 other carbon atoms.
strong covalent bonds make it extremely hard.

Graphite – Made up of layers of carbon atoms. These layers can slide over one another and rub off making graphite soft and good for use in pencils.

Silica – Made up of silicon and oxygen atoms all
covalently bonded together. It is very hard.

Question 6

Electrical conductivity

Answer 6

Diamond doesn’t conduct electricity because there are no free electrons or ions to carry the charge.

Silica is a poor conductor of electricity.

Graphite can conduct electricity because electrons can move within the layers and carry the electrical charge.

Question 7

Melting point and boiling point of covelant bonding

Answer 7

All giant covalent molecules have a high melting point and boiling point.
Covalent bonds are strong so need a lot of
energy (heat) to break.

Question 8

Giant Ionic substances

Answer 8

Giant ionic substances are made up of millions and millions of ions all held together by electrostatic attraction.
These ions all come together to form a giant ionic lattice.

Question 9

Boiling and melting point of ionic substances

Answer 9

To melt or boil a giant ionic substance you have to pull apart the ions and therefore, break the electrostatic attractions.

Electrostatic attraction is very strong and so giant ionic substances have high boiling points and melting points.

Question 10

Electrical conductivity of ionic substances

Answer 10

When the ions are held in place the ions cannot move and so
it cannot conduct electricity.

If a giant ionic substance is molten (melted) then the ions
are free to move and so it can conduct electricity.

Giant ionic substances dissolve in water.
If we dissolve a giant ionic substance in water the ions all move apart and spread out in the water
giant ionic substances can conduct electricity when dissolved.

Question 11

Simple molecular substances

Answer 11

Simple molecular substances are made up of molecules.

The molecules are held together by weak intermolecular forces.

Question 12

Boiling and melting point of simple molecular substances

Answer 12

To melt and boil break the weak intermolecular forces that hold the molecules together as a solid.

These forces are weak so simple molecular substances have low boiling and melting points.

Question 13

Electrical conductivity of simple molecular substances

Answer 13

Simple molecular substances do not conduct electricity
have no free electron or ions to carry the electrical charge.
All molecules form simple molecular substances.
Examples are water (H2O), carbon dioxide (CO2),