1. Lecture: States of Matter

2. There are four states of matter in the universe.
Solids
Liquids
Gases
Plasma (Matter which makes-up the stars)

3. Physical versus Chemical Properties
A Physical Property is a characteristic of a pure substance that can be observed without changing it into another substance. Examples of physical properties are melting temperature, color, hardness, texture, ability to be dissolved, etc…

4. Physical versus Chemical Properties
A Chemical Property is a characteristic of a pure substance that describes its ability to change into different substances. Examples of chemical properties are is the substance flammable, does it react in the presence of certain chemicals, etc..

5. Solids - States of Matter
A fixed, closely packed arrangement of particles causes a solid to have a definite shape and volume.

6. Solids - States of Matter
Solids that are made up of crystals are called crystalline solids.
In amorphous solids, the particles are not arranged in a regular pattern.

7. Liquids - States of Matter
Because its particles are free to move, a liquid has no definite shape. However, it does have a definite volume.

8. Gases - States of Matter
As they move, gas particles spread apart, filling all the space available. Thus, a gas has neither definite shape nor definite volume.

9. Changes Between Solid and Liquid
- Changes of State
Changes Between Solid and Liquid
The change in state from a solid to a liquid is called melting.

10. Changes Between Solid and Liquid
- Changes of State
Changes Between Solid and Liquid
The change of state from liquid to solid is called freezing.

11. Changes Between Solid and Gas
The change in state from a solid to a gas is called sublimation. The change in state from a gas to a solid is called deposition.

12. Temperature and Changes of State
A beaker of ice at –10ºC was slowly heated to 110ºC. The changes in the temperature of the water over time were recorded. The data were plotted on the graph shown here.

13. Temperature and Changes of State
Reading Graphs:
What two variables are plotted on the graph?
Temperature (ºC) on the y-axis, time (minutes) on the x-axis

14. Temperature and Changes of State
Reading Graphs:
What is happening to the temperature of the water during segment C of the graph?
The temperature is rising from 0ºC to 100ºC.

15. Temperature and Changes of State
Interpreting Data:
What does the temperature value for segment B represent? For segment D?
Segment B: melting point of ice; segment D: boiling point of water

16. Temperature and Changes of State
Drawing Conclusions:
What change of state is occurring during segment B of the graph? For segment D?
Change from solid to liquid; change from liquid to gas

17. Temperature and Changes of State
Inferring:
In which segment, A or E, do the water molecules have more thermal energy? Explain your reasoning.
Water molecules in segment E have more thermal energy because they are at a higher temperature.