The atmosphere

Which of the following substances makes up the highest percentage of our atmosphere?

• Carbon dioxide

• Argon

• Oxygen

• Nitrogen

Which of the following processes is used to separate oxygen from air?

• Filtration

• Evaporation

• Fractional distillation

• Crystallization

Which of the following gases relights a glowing splint?

• Oxygen

• Water vapour

• Carbon dioxide

• Hydrogen

Which of the following substances is / are mixture(s)?

(1) Carbon

(2) Muddy water

(3) Sea water

• (1) only

• (2) only

• (1) and (3) only

• (2) and (3) only

Which of the following substances are compounds?

(1) Carbon dioxide

(2) Calcium carbonate

(3) Oxygen

• (1) and (2) only

• (1) and (3) only

• (2) and (3) only

• (1), (2) and (3)

Which of the following statements describes a physical property of the substance concerned?

• Aluminium burns in air to give a white powder.

• Common salt is a white powder

• Iron nails rust in the air

• Potassium reacts vigorously when dropped into water

Matter can be classified into pure substances and mixtures

• True

• False

A compound is a substance composed of two or more elements chemically joined together.

• True

• False

Anything which has mass and occupies space is __________.

Substances which cannot be broken down into anything simpler by chemical methods are _______________.