Topic: Chemistry Aim: Describe the properties and different types of mixtures. Do Now: What is the difference between an element and a compound? HW: Study for tomorrow’s Plant and Ecology Exam

Ozone depletion is the thinning of the ozone layer. Causes of ozone depletion include the release of CFC’s from aerosol cans, refrigerators and air conditions (manufactured before 1995), and the breakdown of foam products. Effects of ozone depletion include more UV radiation hitting the earth’s surface which leads to an increase in skin cancer, increase in cataracts in the eyes, weakening of the immune system and destruction of crops.

Which scenario represents a chemical change? Support your answer.

Chemical change Physical changeChemical change

Tarnishing of silver Chemical change Tarnish is silver sulfides that form from sulfur compounds in the air.

Elements Made up of only ONE type of atom CANNOT be broken down

Compounds Made up of 2 or more different elements CHEMICALLY combined CAN BE BROKEN DOWN

Compounds have properties DIFFERENT from the elements it is made up of Na ClNaCl Compounds have properties DIFFERENT from the properties of the elements that it is made up of.

Element or compound? 1.NaCl 2.O 3.C 6 H 12 O 6 4.CO 2 5.O 2 Compound Element Molecule Compound

Mixtures Pure substance – made up of just water molecules Mix of dissolved substances such as salt, fluoride, calcium carbonate, magnesium, iron, etc…

2 or more substances PHYSICALLY MIXED together but NOT CHEMICALLY COMBINED Ex: –Soil –cake batter –cereal with milk

–Vinegar –Concrete –Wood pencil

For example powdered iron and powdered sulfur mixed together makes a mixture of iron and sulfur. They can be separated from each other without a chemical reaction, in the way that different colored sweets can be picked out from a mixed packet and put into separate piles.

So… what is the main difference between a compound and a mixture? In a compound, substances are CHEMICALLY COMBINE. In a mixture, substances are NOT CHEMICALLY COMBINED. They are PHYSICALLY COMBINED!

ABC Distinguish the element, mixture and compound. Support your answer.

Sugar solution Milk is a combination of water, sugars, proteins, and fats making it a mixture. A sugar solution is a combination of sugar and water.

Vinegar is a combination of acetic acid and water. Jello consists of gelatin and water.

Examples of mixtures: Bowl of fruit loops Rocks in sand at the beach Mixed nuts at a party Puddle of mud (made up leaves, dirt, grasses, etc… Oceans (plants and animals floating around in salt water) Air (mixture of gases)

Solutions Mixture that contains small and dissolved particles

Solute – substance dissolved Solvent – substance that does the dissolving Parts of a solution

A soft drink is a solution that contains several dissolved substances in water.

Let’s summarize… 1.Explain what makes up a mixture. 2.Describe the difference between a compound and a mixture. 3.Explain what makes up a solution.

Review: Which of the following is an example of a mixture of gases? 1.soft drink 2.air 3.oxygen 4.water

In sweetened tea, the sugar is called the 1.solute. 2.solvent. 3.colloid. 4.solution.

Which of the following would help sugar dissolve faster in water? 1.stirring, the water 2.decreasing the solubility of sugar 3.using larger particles of sugar 4.decreasing the water temperature

Which statement is true regarding insoluble substances? 1.They can be easily dissolved in a solvent. 2.An example of an insoluble substance is ice tea dissolving in water. 3.Insoluble substances cannot dissolve in a solvent. 4.They can easily dissolve in a solute.