1. 7-2 States of Matter Introduction to Matter – Course 3

2. How Do You Describe A Solid? SOLID Has a definite shape and a definite volume. The particles that make up a solid are packed very closely together. Each particle is tightly fixed in one position

3. States of Matter Solid The particles that make up a solid are packed very closely together.

4. TYPES OF SOLIDS Crystalline Solids The particles make up a regular repeating pattern that when heated melt at a distinct temperature. Ex. Salt, sugar, and snow. Amorphous Solids The particles are NOT arranged in a regular pattern and do not melt at a distinct temperature, instead they become softer or change into other substances. Ex. Glass, plastic, and rubber

5. States of Matter Types of Solids Use the Venn diagram to compare the characteristics of amorphous and crystalline solids.

6. Assess Your Understanding 1a. The two types of solids are________________________and __________________________. b. Are the particles in a solid motionless? Explain your answer.___________________________________________________ c. Candle wax gradually loses its shape as it is heated. What type of solid is candle wax? Explain. ___________________________________________________ ___________________________________________________ ___________________________________________________

7. How Do You Describe A Liquid? LIQUID Has a definite volume but no shape of its own. The particles in a liquid are packed almost as closely together as a solid but they are able to slide past each other. The particles in a liquid take the shape of their container.

8. States of Matter Liquid Liquid takes the shape of its container, but its volume does not change.

9. Properties Of A Liquid Surface Tension- An inward force, or pull, among the molecules in a liquid that brings the molecules on the surface closer together. Viscosity- A liquid’s resistance to flowing. -high viscosity flows slowly. -low viscosity flows fast and freely. high viscosity low viscosity

10. Assess Your Understanding 2.a.A substance that flows is called a _____________________. b. Why is a liquid able to flow? ___________________________________________________ ___________________________________________________ ___________________________________________________ c. How do liquids with a high viscosity differ from liquids with a low viscosity? ___________________________________________________ ___________________________________________________ ___________________________________________________

11. How Do You Describe a Gas? GAS Has No definite shape and No definite Volume The particles move and spread apart, filling up all the space possible. They move as far apart as they can.

12. States of Matter Gas A gas takes the shape and volume of its container. Describe the arrangement of particles in a gas. _________________________________________ _________________________________________ _________________________________________

13. Pressure of Gas Pressure- the force of its outward push divided by the area of the walls of the container. -Pressure is measured in units of pascals (Pa) or kilopascals (kPa) 1 kPa=1,000 Pa -Pressure = Force Area The air inside an inflated ball has higher pressure than the air outside because it has a higher concentration of gas particles inside the ball than in the surrounding air. (ie. More gas molecules in a smaller space)

14. Temperature of a Gas Temperature which is a measure of how hot or cold something is, is actually a measure of the average kinetic energy of the particles. The hotter the gas, the faster the particles move. The colder the gas, the slower the particles move.

15. States of Matter Temperature of a Gas Why do hot gas particles move faster than cold gas particles? ________________________________________________________

16. Assess Your Understanding 3.a. Explore how the motions of gas particles are related to the pressure exerted by the gas. ___________________________________________________ ___________________________________________________ ___________________________________________________ b. Why does pumping more air into a basketball increase the pressure inside the ball? ___________________________________________________ ___________________________________________________ ___________________________________________________