The diagram shows the arrangement of atom in brass. Why is brass harder than pure copper?

• Zinc atoms form very strong hydrogen bonds with copper atoms.

• Zinc atoms prevent the layers of copper atoms from sliding over each other.

• Zinc atoms prevent electrons from moving freely in the sea of electrons.

• Zinc atom contributes more electrons to the sea of electrons.

The main substance in the making of all types of glass is

• calcium carbonate

• sodium carbonate

• lead(II) oxide

• silicon dioxide

The making of ceramic objects involves the heating of the object at a high temperature in a furnace. Why is this process carried out?

• To remove water

• To keep its shape

• To break all chemical bonds

• To form strong covalent bonds and ionic bonds

Industrial Revolution 4.0 (IR 4.0) will witness the Internet of Things (IOT) in almost all aspects of daily lives. All electronic devices can be connected to the Internet via computer networks. What material is most suitable to make the cables?

• Soda-lime glass

• Borosilicate glass

• Optical cables

• Fibre glass

Which alloy is correctly matched to its uses?

• A

• B

• C

• D

What type of glass is formed when calcium carbonate is heated with silicon dioxide?

• Fused glass

• Borosilicate glass

• Lead crystal glass

• Soda lime glass

The following are the characteristics of substance

needed to produce a new product in industry.

• No electrical resistance

• Function under the extremely low temperature

• Transfer information with high speed

What are the substances that can be used to produce the product?

I Ceramic

II Superconductor

III Fibre optic

IV Fibre glass

• I and III only

• I and IV only

• II and III only

• II and IV only

In order to produce a glass that is more resistant to heat and ceramics, substance X is added to soda lime glass in the manufacturing process. What is X?

• Boron oxide

• Lead(II) oxide

• Sodium carbonate

• Calcium carbonate

Ceramic is suitable to be used for making engine block because ceramic ...

• is inert towards chemical substances.

• is a good electrical insulator.

• can withstand high temperature.

• can withstand strong compression.

Which alloy is correctly matched to its uses?

• Brass - Making musical instruments

• Bronze - Making of surgical instruments

• Stainless steel - Making of monuments

• Duralumin - Making of the body of submarines