Atoms

Question 1

What is the difference between an element, compound and mixture?

Answer 1

• Elements consist of only one type of atom (e.g. oxygen, O₂)
• Compounds are made of two or more different elements which are chemially joined together (e.g. carbon dioxide, CO₂).
• Mixtures are not chemically bonded and can be separated easily (e.g. air).

Question 2

How is carbon dioxide effective at extinguishing fires?

Answer 2

Carbon dioxide is more dense than air and sinks onto flames to stop oxygen from getting to them.

Question 3

How does carbon dioxide make drinks fizzy?

Answer 3

Carbon dioxide is slightly soluble (in water) and dissolves into the drinks when it’s under pressure. The carbon dioxide bubbles are what cause it to be fizzy.

Question 4

What gas makes up most of the air?

Answer 4

nitrogen

Question 5

What pollutant gases form acid rain?

Answer 5

• sulphuric acid
• nitogen oxide

Question 6

What are the problems caused by acid rain?

Answer 6

• Corrosion of metals, such as iron and steel.
• Corrosion of limestone/marble buildings.
• Death of trees.
• Death of aquatic animals (marine/pond life).