Bonding IGCSE edexcel

The ‘lead’ in a pencil is made of a mixture of graphite and clay.

When the percentage of graphite is increased, the pencil slides across the paper more easily.

Which statement explains this observation?

• Graphite has a high melting point.

• Graphite is a form of carbon.

• Graphite is a lubricant.

• Graphite is a non-metal.

Which substance will not conduct electricity?

• aluminium

• copper

• plastic

• steel

Which statement about the Periodic Table is correct?

• Elements in the same period have the same number of outer electrons.

• The elements on the left are usually gases.

• The most metallic elements are on the left.

• The relative atomic mass of the elements increases from right to left.

The table shows properties of four metals.

Which metal is the most suitable for aircraft construction?

• A

• B

• C

• D

Rescuers are drilling through fallen rock in order to rescue some men trapped in a cave. The drill

needs lubricating from time to time.

The following statements were made about the materials used for the drill tip and the lubricant

and the reasons for their use.

1 Diamond was used for the drill tip as it does not conduct electricity.

2 Diamond was used for the drill tip as it is very hard.

3 Graphite was used as the lubricant as it conducts electricity.

4 Graphite was used as the lubricant as it is soft and flaky.

Which statements are correct?

• 1 and 3

• 1 and 4

• 2 and 3

• 2 and 4

In which compounds are pairs of electrons shared between atoms?

1 methane

2 lead bromide

3 sodium chloride

• 1 only

• 2 only

• 1 and 3

• 1, 2 and 3

Diamond and graphite are allotropes of carbon.

Which statement about diamond and graphite is not correct?

• They are giant structures with high melting points.

• They are non-conductors of electricity.

• They contain only atoms of a non-metal.

• They have covalent bonds between the atoms.

The table shows the electronic structure of four atoms.

Which two atoms combine to form a covalent compound?

• W and X

• W and Y

• X and Y

• X and Z

An aluminium atom has a nucleon number of 27 and a proton number of 13.

How many neutrons does this aluminium atom contain?

• 13

• 14

• 27

• 40

The diagram shows an electrical cable.

Which statement about the substances used is correct?

• The coating is plastic because it conducts electricity well.

• The core is copper because it conducts electricity well.

• The core is copper because it is cheap and strong.

• The core is iron because it is cheap and strong.