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Topic: ChemistryAim: 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 Chemical change
Physical change Chemical 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 Cl NaCl
Compounds have properties DIFFERENT from the properties of the elements that it is made up of.
Element or compound?
1.NaCl
2.O
3.C6H12O6
4.CO2
5.O2
Compound
Element
Molecule
Compound
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!
A B C
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.
