1. Chapter 8: Substances, Mixtures, and Solubility Vocabulary 1.Substance – matter that has the same fixed composition and properties. 2.Heterogeneous mixture- type of mixture where substances are not mixed evenly 3.Homogeneous mixture- Contains two or more substances that are evenly mixed on a molecular level but still are not bonded together 4.Solution- a homogeneous mixture that contains two or more substances that are evenly mixed on a molecular level but still are not bonded together 5. Solute- substance that dissolves 6. Solvent- the substance that dissolves the solute 7. Precipitate- solid that comes back out of its solution as a result of a chemical change

2. Chapter 8: Substances, Mixtures, and Solubility Substances (pg. 218) Atoms and Elements Substance is matter that has the same fixed composition and properties Cannot be broken down into simpler parts by ordinary physical processes Only a chemical process can change a substance into one or more new substances.

3. Chapter 8: Substances, Mixtures, and Solubility PHYSICAL PROCESSESCHEMICAL PROCESSES BoilingBurning Changing pressureReacting with other chemicals CoolingReacting with light Sorting

4. Chapter 8: Substances, Mixtures, and Solubility Atoms and Elements (Pg 218 An element is an example of a pure substance; it cannot be broken down into simpler substances The number of protons in an element are fixed; cannot be changed unless the element changes Ex: all atoms with eight protons are oxygen atoms Compounds Water is an example of a substance Always water, even when boiled or frozen It is a compound (made of two or more elements chemically combined) Compounds also have fixed compositions Ratio of atoms in a compound is always the same

5. Chapter 8: Substances, Mixtures, and Solubility Mixtures (Pg 219) Mixtures are combinations of substances that are not bonded together and can be separated by physical processes Ex: salt water, iron filings and sand, pulpy lemonade Mixtures do not always contain the same proportions of the substances they are composed of. Ex: lemonade (see example in text book) Heterogeneous Mixtures Heterogeneous mixture- type of mixture where substances are not mixed evenly Ex: watermelon (fruit and seeds), cold cereal and milk

6. Chapter 8: Substances, Mixtures, and Solubility Homogeneous Mixtures (pg. 220) Contains two or more substances that are evenly mixed on a molecular level but still are not bonded together Solution- another name for a homogeneous mixture Ex: ice pops-molecules of sugar and water are evenly mixed; you cannot see the sugar.

7. Chapter 8: Substances, Mixtures, and Solubility How Solutions Form (pg. 220) Solute- substance that dissolves Solvent- the substance that dissolves the solute The substance that is present in the greatest quantity is the solvent Forming Solids from Solutions Crystallization- when a solute comes back out of its solution to form a solid (when solution is cooled or when some of the solvent evaporates Crystallization is a physical change Precipitate- solid that comes back out of its solution as a result of a chemical change Ex: soap scum in shower

8. Chapter 8: Substances, Mixtures, and Solubility Types of Solutions (pg. 221) Solvent/StateSolute/StateState of Solution Earth’s atmosphere Nitrogen/gas Oxygen/gas/carbon dioxide/gas argon/gas Gas Ocean waterWater/liquidSalt/solid oxygen/gas carbon dioxide/gas Liquid Carbonated beverage Water/liquidCarbon dioxide/gasLiquid BrassCopper/solidZinc/solidsolid

9. Chapter 8: Substances, Mixtures, and Solubility Liquid Solutions (pg. 222) In liquid solutions, the solvent is a liquid The solute can be another liquid, a solid, or a gas The state of the solvent usually determines the state of the solution Liquid-gas solutions Carbonated beverages are liquid-gas solutions Carbon dioxide gives the beverage its fizz and some of its tartness The beverage may contain other solutes such as the compounds that give it its flavor and color

10. Chapter 8: Substances, Mixtures, and Solubility Liquid-liquid Solutions (pg. 222) In liquid-liquid solutions, the solvent and solute are liquids Ex: vinegar (95% water-solvent, 5% acetic acid-solute) Gaseous Solutions (pg. 222-223) Small amount of one gas is dissolved in a larger amount of another gas; gas-gas solution Ex: air we breathe is a gas-gas solution Nitrogen is the solvent (78%) and the other gases are the solutes

11. Chapter 8: Substances, Mixtures, and Solubility Solid Solutions (pg. 223) In solid solutions, the solvent is a solid. The solute can be a solid, liquid or gas The most common solid solutions are solid-solid. A solid-solid solution made from two metals is an alloy It is possible to include elements that are not metals in alloys. ex: steel is an alloy that has carbon dissolved in iron