1. Warm up 10/19/17 Which of the following are pure substances?
Elements only
Compounds only
Both elements and compounds
Neither elements nor compounds
The elements in a compound are…
Bonded together.
Mixed together.
Completely separate.
Easily separated by physical changes.

2. 4.3 Mixtures

3. Mixtures
A mixture is a combination of two or more substances that are not chemically combined.
When substances combine to form a mixture, they do not react.
Example: trail mix is a mixture of nuts, dried fruits, and chocolate chips

4. Separating Mixtures
Because no chemical change occurs, each substance in a mixture retains its properties.
Mixtures can be separated with a physical change.
Pizza toppings still taste like cheese, meat, and veggies

5. Homogenous vs heterogenous
A homogenous mixture looks like a single substance.
A heterogenous mixture looks like two or more substances combined.
Homogenous Mixture Heterogenous Mixture

6. Solutions
When a mixture appears to be a single substance (homogenous), we call it a solution.
Solutions contain a solute (such as salt) which has been dissolved in a solvent (such as water).

7. Alloys An alloy is a solution that is made up of metals.
Steel is an alloy of iron and carbon
Bronze is an alloy of copper and tin
Brass is an alloy of copper and zinc

8. Concentration
The concentration of a solution is a measure of the amount of solute dissolved.
A dilute solution has very little solute
A concentrated solution has a lot of solute
The total amount of solute that can be dissolved is called the solubility.

9. Review questions How is a mixture different from a compound?
What type of change is needed to break apart a mixture?
Does the solubility of sugar increase or decrease as a glass of water is heated?

10. Warm up 10/20/14
A(n) _____________ is a combination of two or more substances that are not chemically combined.
compound
element
mixture
A(n) ____________ is a solution of metals.
alloy
solute
solvent

11. Warm up
The _____________ is the substance that gets dissolved into the solution.
Solute
Solvent
Solution
Solubility
The ____________ is a measure of the amount of solute that can be dissolved.

12. Warm up A(n) _________ contains particles bonded together.
element
compound
solution
mixture
The __________ is the substance that the solute is dissolved into.
Dilution
Solvent
Solution
Solubility

13. Warm up A(n) _________ cannot be broken down into smaller pieces.
element
compound
solution
mixture
The amount of a substance you can dissolve is the...
Dilution
Solvent
Solution
Solubility