bonding + chemical structure

Question 1

covalent bond

Answer 1

There is a strong attraction between the shared pair of electrons and the nuclei of the atoms involved.

Question 2

simple covalent structure

Answer 2

Simple covalent structure =Weak interolecular forces= not mutch energy to overcome= low melting points

Question 3

Diamond

Answer 3

Diamond has a high melting and boiling point due to the strong covalent bonds between carbon atoms. It is very hard so cannot be scratched and can be used in cutting tools.
It does not conduct electricity as there are no free moving ions or electrons.

Question 4

graphite

Answer 4

Shiny black solid.
The carbon atoms are arranged in layers. Each carbon atom is covalently bonded to 3 other carbon atoms.
The strong covalent bonding within each layer means that it takes a lot of energy to break the bonds. So, the melting and boiling points are very high.
The forces between the layers are weak and can slide over each other.
Graphite is used as a lubricant and in pencils.

Question 5

Buckminster fullerene (C60)

Answer 5

This has a simple covalent structure. It contains 60 carbon atoms, each of which bonds with 3 others.
This has a lower melting and boiling point.

Question 6

Silicon dioxide

Answer 6

Similar structure to diamond.
Each silicon atom is bonded to 4 oxygen atoms, but each oxygen is only bonded to 2 silicon atoms.
Similar properties to diamond. It has a high melting and boiling point. It takes a large amount of energy to break the strong covalent bonds.
It does not conduct electricity because it has no delocalised electrons.

Question 7

ionic bonding

Answer 7

strong electrostatic attractions between oppositely charged ions which require a lot of energy to overcome

Question 8

Methane (CH₄)

Answer 8

Simple molecular structure. Weak intermolecular forces = gas at room temperature.