Pure Substances And Mixtures Flashcards
1
Q
What is an element?
A
A substance that consists only of atoms with the same atomic number
2
Q
What is a compound?
A
A compound is a substance that consists of atoms of two or more different elements chemically joined together
3
Q
What do elements exist as?
A
Atoms or molecules
4
Q
What is meant by a pure substance?
A
A substance containing only one element or compound
5
Q
The label on a bottle describes the contents as “pure mineral water”‘Explain why the water is not pure in the scientific sense.
A
A pure substance contains only one element or compound but mineral water will be a mixture of water and other substances
6
Q
Different combinations of atoms result in what?
A
Different compounds
7
Q
How do you make a pure salt?
A
- Heat sulphuric acid
- Stir in copper oxide until it is in excess
- Let it cool
- Go to solution to remove the excess copper oxide
- Evaporate the liquid
