1. Atom The “smallest piece” of matter that still keeps all the properties of the element (we will talk about properties later) All matter is composed of atoms

2. Atom Have we ever seen atoms? Yes – ever since the invention of the scanning tunneling electron microscope in 1981 by Nobel Laureates Gerd Binnig and Heinrich Rohrer Platinum atoms

3. Molecule Another “smallest piece” of matter – but are made of two or more atoms. All matter is composed of molecules

4. Molecule

5. Matter - Anything that has mass and takes up space

6. Pure Substance: is either an Element or a Compound

7. Element- Has only one kind of atom, found on the periodic table

8. Examples of Elements Anything on the periodic table H He ONe KAr NKr CXe CaRn

9. Compound - Substance with two or more kinds of atoms bound together

10. Example: Water The elements hydrogen and oxygen combine

11. Example : Salt The elements sodium and chloride combine (NaCl)

12. Mixture – is a impure substance made of two or more things mixed together Can be separated by physical means,

13. Homogeneous mixture- Evenly mixed mixture Sometimes called a solution

14. Examples of solutions Salt Water Rubbing Alcohol

15. Heterogeneous mixture- Unevenly mixed mixture *Different materials can be seen

16. Examples: Italian dressing, Concrete, Pizza

17. Colloids- A heterogeneous mixture that never settles and scatters light

18. Examples: gelatin, whipped cream

19. Examples: milk, fog

20. Suspension- A type of mixture in which visible particles settle

21. Examples: muddy water, Italian dressing, snow globes