Extraction of metals & uses of metals

Which of these elements is unlikely to be found native?

• gold
• platinum
• aluminium
• silver

Many metals are extracted from their ores by heating the metal oxide from carbon.

Which metal cannot be extracted using this method?

• aluminium

• copper

• iron

• zinc

Iron is extracted from its ore (hematite) in the blast furnace.

Which gas is produced as a waste product?

• carbon dioxide

• hydrogen

• nitrogen

• oxygen

Which substance is not involved in extraction of iron from hematite?

• carbon

• carbon monoxide

• calcium carbonate

• nitrogen

In the extraction of aluminium, what compound of aluminium is used for the electrolyte?

• aluminium oxide

• aluminium sulfate

• aluminium nitrate

• aluminium sulfide

In aluminium extraction, the melting point of the electrolyte is lowered by adding (a)  

Copper is a transition element used to make saucepans.

Which property is not correct for copper?

• good conductor of heat

• insoluble in water

• low melting point

• malleable

Which two elements make up mild steel?

• aluminium & magnesium

• copper & zinc

• iron & carbon

• tin & lead

Which statements is not correct?

• aluminium - used in food container because of its resistance to corrosion

• aluminium - used in manufacture of aircraft because of its strength and low density

• mild steel - used in car bodies because of its strength and low density

• stainless steel - used in chemical plant because of its strength and resistance to corrosion

What are the advantages of recycling metals? Select all correct options.

• Conserves metals as they are finite resources.

• Reduces waste and problems in its disposal.

• Takes time to collect and sort waste metals.

• Reduces pollution due to extraction activities.