How are metal oxides formed?

• When metals react with oxide.
• When metals react with water.
• When metals react with air.
• When metals react with oxygen.

Which of the following is the product of the reaction of aluminium and oxygen?

• aluminium oxide.
• metal oxide
• aluminium ore
• aluminium and oxygen

Aluminium ore is also known as

• haematite
• bauxite
• ore
• rock

Which of the following reactions produces calcium oxide?

• calcium and oxide
• calcium and water
• calcium and air
• calcium and oxygen

Which of the following defines oxidation?

• A chemical reaction where a substance gains oxygen.
• A chemical reaction where a substance loses oxygen.
• A chemical reaction where a substance loses a metal.
• A chemical reaction where a substance gains a metal.

Which of the following is an example of an oxidation reaction?

• Ca  +   O₂ --> CaO
• Na₂O  + H₂O --> NaOH
• Fe₂O₃   + CO --> Fe   +  CO₂
• All of the choices are oxidation reactions.

Which of the following is an example of an reduction reaction?

• Ca  +   O₂ --> CaO
• Na  + O₂ --> Na₂O
• Fe₂O₃   + CO --> Fe   +  CO₂
• All of the choices are reduction reactions.

The rusting of iron is an example of

• a reduction reaction.
• an oxidation reaction.
• a reaction of iron with water.
• a reaction that dissolves iron.

When metals are extracted from ores, a __________ reaction is used.

• oxidation.
• reduction.
• extraction
• mining

The process of extracting ores from the ground is called

• extraction.
• mining.
• reduction.
• oxidation.