Chapters 2, 3, 7 Review Slides

Chapter 2

What is Matter?

*How many particles in a certain amount of space

Chapter 3

Kinetic Theory of Matter 1. All matter is made of atoms and molecules that act like tiny particles 2. These particles are always in motion. -The higher the temperature, the faster they move 3. At the same temperature, heavier particles move slower than lighter particles

Energy Thermal Energy The total kinetic energy of particles that make up an object. The faster a particle move, the more kinetic energy it has, and the greater the object’s thermal energy is. Temperature A measure of average kinetic energy The more kinetic energy an object has, the higher the temperature

Energy released Energy absorbed Endothermic: Energy is absorbed Exothermic: Energy is released

Conservation of Mass and Energy Conservation of Mass Mass cannot be created or destroyed Total mass of matter stays the same before and after the change Conservation of Energy Energy cannot be created or destroyed Energy may be converted to another form during a change but the total amount of energy before and after the change is the same.

Chapter 7

Heterogeneous vs. Homogeneous Mixtures Heterogeneous: the amount of each substance in different samples varies Example: Fruit Salad Homogeneous: uniform throughout Example: Salt Water

Suspensions vs. Colloids Suspension: a mixture in which particles of a material are more or less evenly dispersed throughout a liquid or a gas -The particles will settle out when the mixture is allowed to stand -Example: Orange Juice Colloid: mixture of tiny particles that are suspended in a solid, liquid, or a gas -The particles are smaller in a colloid than a suspension -Example: Latex Paint, Fog

Solutions Solution: Homogeneous mixture of two or more substances uniformly dispersed throughout a single phase Solute: the substance that dissolves in the solvent Solvent: the substance in which the solute dissolves

Which is the solvent and which is the solute? 1. You are making hot chocolate with milk and chocolate mix. 2. You put sugar in your coffee. 3. You are making Kool-aid and mix the package with cold water.

Like Dissolves Like -A solvent will dissolve substances that are like the solvent in molecular structure. -Polar molecules will dissolve polar molecules -Example: Water will dissolve sugar -Nonpolar molecules will dissolve nonpolar molecules -Example: Water will not dissolve oil

Ways to Make Solutes Dissolve Faster 1. Stir the mixture 2. Heat the mixture 3. Shake the mixture 4. Break the mixture down into smaller pieces