2. Mixtures Mixture= a combination of 2 or more substances that are not chemically combined or react to form a compound Example: pizza!

3. Mixture 2 or more different pure substances are not chemically combined Can be physically separated Sand and ironSalt and water No chemical reaction needed Each part of the mixture retains its own properties. Nothing is changed Sand and water

4. In a mixture, the ratio of parts can change. In a pure substance, they cannot. Salt water can contain little salt or a lot of salt.

5. Mixtures Each substance in a mixture keeps its identity Example: all ingredients on a pizza keep their identity and do not react Mixtures can be physically separated Example: you can pick off the cheese or topping you do not like on a pizza

6. Ways to separate a mixture: Separation Technique Name DefinitionExample DistillationProcess that separates a mixture based on the boiling point of the components Water purification MagnetComponents are attracted to the magnet and separate out Iron can be separated with a magnet CentrifugeMachine that separates mixtures according to their densities Blood HeatProcess of heating and separating a liquid from a solid Salt water * More than one technique can be used to separate a mixture

7. Mixtures VS. Compounds MixturesCompounds Components are elements, compounds, or both Components keep their original properties Separated by physical means Formed using any ratio of components Components are elements only Components lose their original properties Separated by chemical means Formed using a set mass ratio of components

8. Review! 1. What is a mixture? 2. Is a mixture separated by physical or chemical means? 3. How would you separate iron filings from sawdust? Explain.

9. Can you identify the following? You will be shown a series of photos. Tell if each photo represents an item composed of an element, compound, or mixture. Review: An element contains just one type of atom. A compound contains two or more different atoms joined together. A mixture contains two or more different substances that are only physically joined together, not chemically. A mixture can contain both elements and compounds.

10. Element, Compound, or Mixture? Rocks

11. Element, Compound, or Mixture? Rocks

12. Element, Compound, or Mixture? Copper

13. Element, Compound, or Mixture? Copper

14. Element, Compound, or Mixture? Jelly Beans

15. Element, Compound, or Mixture? Jelly Beans

16. Element, Compound, or Mixture? Table Sugar

17. Element, Compound, or Mixture? Table Sugar

18. Element, Compound, or Mixture? Diamond

19. Element, Compound, or Mixture? Diamond

20. Element, Compound, or Mixture? Tea

21. Element, Compound, or Mixture? Tea

22. Element, Compound, or Mixture? Salt

23. Element, Compound, or Mixture? Salt

24. Element, Compound, or Mixture? Neon Gas

25. Element, Compound, or Mixture? Neon Gas

26. Element, Compound, or Mixture? Salad

27. Element, Compound, or Mixture? Salad

28. Element, Compound, or Mixture? Pure Water

29. Element, Compound, or Mixture? Pure Water

30. Element, Compound, or Mixture? Aluminum

31. Element, Compound, or Mixture? Aluminum

32. Element, Compound, or Mixture? Lemonade

33. Element, Compound, or Mixture? Lemonade

34. Element, Compound, or Mixture? Silver

35. Element, Compound, or Mixture? Silver

36. Element, Compound, or Mixture? Sand

37. Element, Compound, or Mixture? Sand