Chapter 1 | Pure Substances

Question 1

What’s the difference between mixtures and pure substances?

Answer 1

Mixtures : 2 or more kinds of particles/substances

Pure Substance : 1 kind of particle

Question 2

Name the different types of pure substances :

Answer 2

• Elements

- Compounds

Question 3

What’s an element?

Answer 3

It’s a pure substance that contains 1 type of atom ;

• Impossible to separate into different substances chemically

Question 4

What’s a compound?

Answer 4

It’s a pure substance that contains at least 2 kinds of atoms

• Possible to separate into different substances

Question 5

What’s the periodic table?

Answer 5

The periodic table is a way for chemists to organize all of the elements in the known universe

• Each element is a different substance

Question 6

Name the properties of pure substances :

Answer 6

Non-Characteristic Properties :
- Temperature
- Shape
- Mass
- Volume
- Phase/State
Characteristic Properties :
- Colour
- Density
- Boiling Point
- Freezing Point
- Solubility

Question 7

Give some examples of Characteristic Chemical properties :

Answer 7

Reaction to :

1. Litmus Paper
   - Acid makes it go Red
   - Bases makes it go Blue
2. Glowing Splint
   - O² lights it
3. Lit Splint
   - H² “pops”
4. Open Flame
   - Puts our flame
   - Barium turns Green
   - Potassium turns Purple
   - Strontium turns Red
5. Limewater
   - CO² makes it cloudy

Question 8

Characteristic Properties do what?

Answer 8

They can help us identify unknown substances

Question 9

Name different ways to separate mixtures:

Answer 9

1. Centrifugation
2. Filtration
3. Evaporation
4. Distillation
5. Chromatography