2. Topic 2 – Changes in Matter
YAY! Chemistry! 
Topic 2 – Changes in Matter

3. Properties
Every kind of matter has certain properties that can help to classify it.
Properties are the characteristic ways in which a substance behaves.

4. Properties Physical Property
Any property that can be observed or measured without forming a new substance
Examples:
Density
Color
Texture
Smell

5. Examples:
Let’s look at two things and describe some of the physical properties of them.
1. Sugar
2. Icing Sugar

6. What do you know?!
QUALITATIVE
QUANTITATIVE

7. Qualitative and Quantitative
There are two types of physical properties
QUALITATIVE
QUANTITATIVE
Colour
Melting temperature
Texture
Boiling temperature
Taste
Density
Smell
Viscosity
Crystal Shape
Solubility
Malleability
Electrical Conductivity
Heat Conductivity

8. Chemical Properties The way substances react with other substances.
Examples:
Reacts with water – Sodium (Alkali Metals)
Reacts with air – Pure iron (rust)
Reacts with pure oxygen
Reacts with acids
Toxicity
Stability (radioactive) - Uranium
Combustibility

9. Example – Table Salt (Sodium Chloride – NaCl)
Physical Properties:
Appearance: colourless crystals or white powder Melting point: 804 C Boiling point: 1413 C
Chemical Properties:
Toxicology: May cause eye irritation
Reacts with water: No
Reacts with Air: No

10. Example of Properties
You have two balloons. One is filled with hydrogen and one is filled with helium. How will you tell which is which?
Properties
Helium
Hydrogen
Color
Colourless
Density
Low (0.18 g/L)
Very Low (0.09 g/L)
Combustibility
Does not burn
Burns explosively

11. Properties can CHANGE! How can properties change?
Lets look at a piece of paper.
What does it look like? What does it feel like? What is it used for?

12. Two kinds of changes Physical Change
A substance changes in form but not in chemical composition
NO NEW SUBSTANCES ARE FORMED
EXAMPLE:
Ice melting. This is a state change that can be easily reversed
Paper crumpling
Salt dissolved in water

13. Properties of Matter
Physical Changes

14. Chemical Change Causes one or more new substances to be formed.
A chemical change may be difficult or impossible to reverse
Examples:
Burning paper – the smoke that escaped and the black solid that is left behind (carbon) cannot be recombined to form paper again

15. How do you tell if it is physical or chemical?
IT CAN BE VERY DIFFICULT TO TELL IF SOMETHING IS A PHYSICAL OR CHEMICAL CHANGE

16. If you make TWO OR MORE of the following observations, then a CHEMICAL CHANGE has probably taken place
1. Heat is produced or absorbed
2. The starting material is used up
3. There is a change in color
4. A material with new properties forms
5. Gas bubbles form in a liquid
6. A precipitate forms in a liquid
7. The change is difficult to reverse.

17. Changes in Matter Physical Changes Chemical Changes
A substance changes form but not chemical composition
Chemical Changes
Causes one or more new substances to be formed. It may be impossible to reverse.