Compounds and mixtures

Which of the following is a compound?

• coffee

• juice drink

• milk shake

• sodium chloride

• nasi goreng

Which of the following is a mixture?

• air

• nitrogen

• iron sulfide

• milk shake

• iron oxide

True or False: Air is a compound.

• True

• False. It is a mixture of many non-metals.

• False. It is a mixture of various elements and compounds.

• False. It is a mixture of water and carbon dioxide only.

When iron reacts with oxygen, the compound formed is called ________.

• iron sulfide

• iron dioxide

• iron oxygenide

• iron oxide

Iron can be separated from sulfur in their mixture. Why?

• Iron is hard while sulfur is soft.

• Iron is magnetic while sulfur is not.

• Iron conducts electricity while sulfur cannot.

• Sulfur conducts heat while iron cannot.

• Sulfur is magnetic while iron conducts heat.

Iron and sulfur, when heated, forms a compound. It is not easy to separate iron because ...

• Iron is a metal and sulfur is a non-metal.

• Iron loses its magnetic properties when in a compound.

• Sulfur loses its brittleness.

• Sulfur loses its conductivity to heat.

• Iron loses its electrical conductivity.

Which of the following is NOT present in the air as shown in the video?

• carbon dioxide

• oxygen

• nitrogen

• water vapour

• sulfur dioxide

Which of the following is a property of sulfur?

• It conducts heat.

• It conducts electricity.

• It is a yellow liquid.

• It is a non-metal.

What happens when iron and sulfur are heated together?

• Iron sulfur is formed.

• Iron sulfuride is formed.

• Iron sulfide is formed.

• Iron sulfate is formed.

Which of the following is a property of the compound iron sulfide?

• It conducts electricity like iron.

• It is brittle like sulfur.

• It is magnetic like iron.

• It is not magnetic and does not conduct heat.