Matter Key Questions: What’s the difference between an element, compound, and mixture? What’s the difference between an element, compound, and mixture? How are the particles different in a solid, liquid, and gas? How are the particles different in a solid, liquid, and gas?

Intro Lab Thingy As a table, get: As a table, get: Test Tube holder Test Tube holder Test tube Test tube Beaker of water Beaker of water Cup of salt Cup of salt Spatula Spatula Fill the test tube to the brim with water and place it in the test tube holder Fill the test tube to the brim with water and place it in the test tube holder Listen for further directions Listen for further directions

Intro Lab Thingy 2 Add little scoops of salt until the water just flows over the top- how many did you get? Add little scoops of salt until the water just flows over the top- how many did you get? Clean it all up: Clean it all up: Dump and rinse test tube Dump and rinse test tube Wipe table with paper towels Wipe table with paper towels Leave leftover salt in dish for next class Leave leftover salt in dish for next class Put everything back at the back table Put everything back at the back table

You already reviewed… Chemical and Physical Changes Chemical and Physical Changes Indicators of chemical change: Indicators of chemical change: Bubbles Bubbles Color change Color change Light Light Can’t go back to starting materials Can’t go back to starting materials Element/Compound/Mixture Element/Compound/Mixture Changes of State Changes of State

Elements A substance which contains only one kind of atom: lead (Pb), silver (Ag), hydrogen (H 2 ), oxygen (O 2 ). A substance which contains only one kind of atom: lead (Pb), silver (Ag), hydrogen (H 2 ), oxygen (O 2 ).

Compounds A substance which contains two or more kinds of atoms: A substance which contains two or more kinds of atoms: carbon dioxide (CO 2 ), calcium oxide (CaO), sodium hydroxide (NaOH) carbon dioxide (CO 2 ), calcium oxide (CaO), sodium hydroxide (NaOH)

Mixtures Substances held together by physical forces, not chemical. Substances held together by physical forces, not chemical. The individual molecules enjoy being near each other, but their fundamental chemical structure does not change when they enter the mixture. The individual molecules enjoy being near each other, but their fundamental chemical structure does not change when they enter the mixture.

Solids, Liquids and Gasses Matter commonly exists in one of three states of matter Matter commonly exists in one of three states of matter Solid: Definite shape, particles are packed close together Solid: Definite shape, particles are packed close together Liquid: Definite volume, particles are spaced apart Liquid: Definite volume, particles are spaced apart Gas: Indefinite shape and volume, particles widely spaced Gas: Indefinite shape and volume, particles widely spaced

Plasma Plasma: an ionized gas, a gas into which sufficient energy is provided to free electrons from atoms or molecules Plasma: an ionized gas, a gas into which sufficient energy is provided to free electrons from atoms or moleculeselectrons

Kinetic Theory All matter is made of particles (atoms or molecules) All matter is made of particles (atoms or molecules) Particles in constant motion (above 0 K, absolute zero) Particles in constant motion (above 0 K, absolute zero) As energy increase particles move from solid to liquid to gas As energy increase particles move from solid to liquid to gas

Watch This… Demo #1: Ball and Hoop Demo #1: Ball and Hoop Demo #2: Flask and glass tubing Demo #2: Flask and glass tubing Demo #3: Baking soda and vinegar- hot and cold Demo #3: Baking soda and vinegar- hot and cold

Freezing / Melting Freezing: Energy decreases enough so that particles slow down to create an ordered, attractive, definite shape Freezing: Energy decreases enough so that particles slow down to create an ordered, attractive, definite shape Melting: an increase in energy enables particles to flow around each other

Boiling / Condensing Boiling point: the temp at which the vapor pressure is equal to the external pressure of a liquid Boiling point: the temp at which the vapor pressure is equal to the external pressure of a liquid

Evaporation / Sublimation Evaporation: vaporization occurs at the surface of the liquid without boiling Evaporation: vaporization occurs at the surface of the liquid without boiling Sublimation: Direct conversion Sublimation: Direct conversion from a solid to a gas from a solid to a gas

Heating Curve… Why? Particles Speeding Up Particles Spreading Out Solid Solid + Liquid Liquid Liquid + Gas Solid Gas Cooling Curve

Particles Spreading Out Particles Speeding Up Solid Gas + Liquid Gas Liquid Solid + Liquid Boiling Point Freezing Point Melting Point Particles Spreading Out Particles Speeding Up Solid + Liquid Liquid Gas Gas + Liquid Solid Boiling Point Freezing Point Melting Point

Heating Curve… Why? Solid