C3 - Structure and Bonding

Question 1

C3 - Describe what happens when sodium and chlorine bond

Answer 1

Ionic bonding is when atoms lose or gain electrons to have a full outer shell.
This type of bonding normally happens between a metal (sodium) and a non-metal (chlorine).

When sodium and chlorine bond:
Sodium gives its outer electron to chlorine.
Sodium becomes positively charged
Chlorine gains an electron from sodium.
Chlorine becomes negatively charged.
Both atoms are now ions.
Both atoms now have a full outer shell.

Question 2

C3 - Describe what happens during covalent bonding

Answer 2

When atoms bond covalently they share pairs of electrons in order to get a full outer shell.

This usually occurs between two nonmetal atoms.

One set of electrons are drawn with crosses.

One set of electrons are drawn with dots.

This helps us work out where the electrons have come from.

The shared pair of electrons is drawn in the middle of the two atoms.

Question 3

C3 - Explain why ionic compounds have high melting and boiling points

Answer 3

Ionic compounds form giant lattices (repeated structure).

There are strong electrostatic forces between oppositely charged ions.

Lots of energy is needed to overcome these forces.

Question 4

C3 - Explain why diamond is very strong.

Answer 4

Diamond is made from carbon.

4 covalent bonds per atom.

Covalent bonds are very strong.

Each carbon atom forms the maximum number of bonds it can (4).

Many strong bonds = lots of energy required to break them.

Question 5

C3 - Explain why graphite is soft

Answer 5

Because:

Weak forces between layers of graphene.

Layers can slide over each other

Layers can be pulled apart easily.

Question 6

C3 - Explain why graphite can conduct electricity.

Answer 6

Conducts electricity because:

Only 3 bonds per carbon atom.

Each carbon atom has a spare electron.

This electron delocalizes and conducts electricity.

Question 7

C3 - Describe the bonding structures that occur in metals.

Answer 7

Lattice of positive metal ions arranged in regular layers.

Outer electrons delocalise to form a sea of free moving electrons.

Strong electrostatic forces between positive metal ions and negative sea of electrons.

Question 8

C3 - Explain how the bonding structures in metals give them their properties.

Answer 8

Bonding structure = property.

Outer electrons delocalise = metals conduct electricity.

Strong electrostatic forces between ions and sea of electrons = high melting and boiling points.

No bonds between adjacent ions = ions can slide over each other - malleable.