1. Chapter 7
Kinetic Molecular Theory Explains the Characteristics of Solids, Liquids, and Gases.

2. 7.1 – States of Matter Matter, Mass, Volume
Matter: anything that has mass and volume Mass: the amount of matter in an object (measured in g or kg) Volume: amount of space taken up by a substance or object

3. The Particle Model of Matter
All matter is made up of very small particles.
There are spaces between the particles.
The particles are always moving.
The particles are attracted to each other.

4. Kinetic Energy
Kinetic Energy = the energy of motion All particles in every solid, liquid and gas are always moving, so they have KINETIC ENERGY

5. The Kinetic Molecular Theory
All matter is made up of very small particles.
There is empty space between particles.
Particles are always moving and they bump into each other and their container.
a. SOLIDS – tightly packed; can’t move freely; only vibrating
b. LIQUIDS – farther apart; slide past each other
c. GASES – very far apart; move around quickly
Energy makes particles move.

6. Thermal Expansion and Contraction
Matter expands (gets bigger) when its temperature is increased (energy is added)
Contraction Matter contracts (gets smaller) when its temperature decreases (energy taken away)

7. Heat and Temperature
Heat – energy transferred from one thing to another because they are different
Temperature – reading of the average kinetic energy of its particles

8. Changes of State

9. Changes of State Example

10. 7.2 – Fluids and Density
Fluid – any form of matter that can flow Remember: Fluids FLOW

11. Fluids List as many fluids as you can
How can we make fluids flow more quickly?

12. Density
Density - the mass of a given volume.

13. Layers of Fluids

14. Measuring Density Layering
Allows you to determine whether one substance is denser than another
Does not give a specific measurement of density

15. Measuring Density (2) Displacement
Amount of space an object takes up when placed in a fluid
Measuring displacement of an object gives you its volume

16. Measuring Density (3) Finding mass and volume
Mass can be found using a scale
Volume can be measured in mL for liquids and cm³ for shapes
NOTE: 1 mL = 1 cm³

17. Calculating Density
Once you know mass and volume you can calculate density using the formula:
𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝐷 = 𝑚𝑎𝑠𝑠 (𝑚) 𝑣𝑜𝑙𝑢𝑚𝑒 (𝑉) (𝐷= 𝑚 𝑉 )
Example:
1 mL of glycerol has a mass of 1.26 g. What is the density of glycerol?