1. Solids, Liquids, and Gases
Lesson 3 Unit 2

2. Reading Guide:
Essential Question: How does energy affect the properties of matter?
Vocabulary:
Solid
Liquid
Gas
Temperature
Melting point
Freezing point
Boiling point

3. What are the states of Matter?
A state of matter is a form that matter can take. On Earth, there are three forms of matter: solid, liquid and gas.
Matter is made of atoms. These particles are always in motion, but the motion may differ depending on the state of matter.
In solids, atoms are tightly packed and the bonds between each particle is connected. Their motion is a slight vibration.
Liquids have atoms no longer connected, but they are still attracted to one another. The atoms flow pass one another.
Gas have not connection or attraction and lack a definite shape or a definite volume.

4. What are the states of Matter?

5. How does heat affect the state of matter?
Atoms are in constant motion and that motion depends on the amount of energy the atoms possess.
If the particles are moving, they possess kinetic energy. The more kinetic energy a moving object has the faster and further apart it moves. Moving objects with less energy move more slowly and stay closer together.
The amount of kinetic energy an object possesses depends on its temperature. Temperature is the measurement of the average kinetic energy of the particles in a material.
Substances can change from one state of matter to another when energy is absorbed or released.

6. How does heat affect the state of matter?

7. How does heat affect the state of matter?
When a solid absorbs enough energy it can change into a liquid. This is called the melting point. If enough energy is added, the liquid can change into a gas.
When energy is removed (temperature dropped), the particles slow down and group together to form new states of matter. A gas becomes a liquid, and a liquid becomes a gas.
The change from a liquid to a solid state is called freezing point.
Sublimation occurs when a substance changes directly from a solid to a gas going through a liquid state.

8. How does heat affect the state of matter?

9. How does heat affect the state of matter?

10. When does matter change states?
The melting point of a substance is the point at which it melts and becomes a liquid
The Freezing point of the substance is the temperature at which a liquid changes to a solid
The boiling point is the temperature at which a liquid turns into a gas
When vaporization takes place at the surface of a liquid is called evaporation.
When vaporization occurs below the surface, it is called boiling.
Condensation occurs when a gas cools, its particles slow down, and it becomes a liquid.
Each substance has its own freezing and boiling point because it requires different amount of energy to break the bonds of its particles.

11. When does matter change states?

12. When does matter change states?

13. What is air pressure?
Air pressure is the force exerted onto a surface by the weight of the air.
For example, the gas particles inside the balloon move around rapidly and hit the inner surface of the balloon.
Increasing pressure on the gas decreases its volume.
If its volume increases its pressure will decrease.
Gases contract when the temperature drops and expand when they are heated.

14. What is air pressure?