1. Counting Atoms and Elements

2. Atom vs Element A substance composed of only one kind of atom – it cannot be broken down into simpler substances by ordinary means. Examples: Hydrogen H, Oxygen O, Aluminum Al The smallest particle of matter that displays the properties of an element.

3. Pure Substance A substance in which there is only ONE type of particle and cannot be separated by ordinary physical means. Example: Na or NaCl

4. OHH2OH2O LET’S Count ELEMENTS! What Elements do you see? How many elements do we have total? 1 (Hydrogen) + 1 (Oxygen) = 2 Total Elements

5. H2H2 OH2OH2O LET’S Count Atoms! We have 2 elements. We now have to find how many of each element we have. What does the subscript (2) tell us about Hydrogen? Elements# of Atoms Hydrogen2 How many Oxygen atoms do we have? Elements# of Atoms Hydrogen2 Oxygen1 So how many total atoms do we have? 3 Total Atoms in H 2 O

6. COMPOUNDTOTAL NUMBER OF ELEMENTS NAMES & NUMBERS OF ATOMS OF EACH ELEMENTTOTAL ATOMS As 2 S 3 AlCl 3 BaCl 2 MnBr 2 CaS SrCl 2 HgBr K2SK2S Fe 2 O 3 H 2 SO 4

7. Chemical Reactions Day 2

8. Chemical Reaction Process by which chemical changes occur. Atoms are rearranged and chemical bonds are broken and formed. Chemical Reactions from the Periodic Table Watch This!

9. Reactants The ingredients in the beginning of a chemical reaction that are changed into a new substance. Yield (Produce) Products Substance formed by a chemical reaction. It is made by the rearrangement of atoms and bonds in the reactants. Chemical Equation C + O 2 Using symbols and chemical formulas to illustrate a chemical reaction. CO 2

10. Now Let’s Challenge Ourselves

11. 2NaI2 I2I2 2Na2+ We are going to Count the Atoms and Elements in an Equation! Coefficient A number written in front of a formula used to balance a chemical equation. It multiplies the # of atoms in a formula. Na + I I I I 2Na + I 2

12. I2I2 2KCl Cl 2 2KI+ 2KCl + I 2 2KI + Cl 2 K K + I I K K CI + I I How many Elements do we have for both reactants & products? K ICl REACTANTS KICl Products How many Atoms do we have for both reactants & products? REACTANTS K - 2 I - 2 Cl - 2 Products K -2 I - 2 Cl - 2

13. ClPbILiIPbClLi2LiCl + PbI 2 2LiI + PbCl 2 REACTANTSPRODUCTS Elements Total: 4

14. 2LiCl + PbI 2 2LiI + PbCl 2 REACTANTSPRODUCTS Atoms Li Cl Pb I Li Cl Pb I 2 2 1 2 Total: 7 2 2 1 2

15. OFeO 4Fe + 3O 2 2Fe 2 O 3 REACTANTSPRODUCTS Elements Total: 2

16. 2 2 3 2 2 3 4Fe + 3O 2 REACTANTS PRODUCTS Atoms Total: 10 Fe 2 + Fe 2 Fe + x O O 4 O 3 + O 3 O O O O + O O 6 2Fe 2 O 3 4 O 2 + O 2 + O 2 OO + OO x x 6 O + O

17. ZnClHHZnClZn + 2HCl ZnCl 2 + H 2 REACTANTSPRODUCTS Elements Total: 3

18. Zn + 2HCl ZnCl 2 + H 2 REACTANTSPRODUCTS Atoms Total: 5 Zn Cl H Zn Cl H 1 2 2 1 2 2

19. Balancing Chemical Equations Day 3

20. When balancing an equation we want to have… 1. The same number of Elements on the Reactants side and on the Products side 2. The same number of Atoms of each element on the Reactants side and on the Products side LET’S GIVE IT A TRY :D

21. Li + Cl 2 LiCl Let’s Balance!Let’s Balance! What Elements do we have on the Reactant side? Li Cl What Elements do we have on the Product side? Li Cl How many Lithium and Chlorine are there on the reactant side? 1 2 How many Lithium and Chlorine are there on the product side? 1 1 We are not Balanced! We can add Coefficients to try and balance the equation. * Remember Coefficient will multiply the number of atoms X 2 2 2 X X 2 2 Now Li is not Balanced! X 2 2 2 X 2 Balanced!Balanced!

22. Law of Conservation of Mass In a chemical reaction, atoms are not created nor destroyed. Each element will have the same # of atoms on both sides of the reaction.

23. Law of Conservation of Mass Each element will have the same # of atoms on both sides of the reaction. 2Li + Cl 2 2LiCl Li 2Cl 2

24. Let’s do a few more examples!

25. BrAlBrAl Let’s Balance!Let’s Balance! Al + Br 2 AlBr 3 What elements are we working with on the reactant side? What elements are we working with on the product side? How many Atoms are on the reactant side? 1 2 How many Atoms are on the product side? 1 3 X 22 2 6 2 2 2 2 X 33 3 6 Balanced!Balanced!

26. Na + O 2 Try this one on your own! Na 2 O ELEMENTSATOMS ReactantsProducts Na O O 2 1 2 1 2 4 2 4 4

27. Professor Frankenstein is conducting a science lab. He has 140g of sodium and wants to combine it with 80g of water. What will be the mass of the product? 140g Na + 80g water = 220g of product

28. Witch Hazel is making a spooky brew for her upcoming party. She has 115g of bubble juice. She forgot to write down how much liquid fog she added. The product has a mass of 160g. Calculate the amount of liquid fog she added. 160g Brew - 115g bubble juice = _____g of liquid fog

29. Chemical Reaction Lab DAY 4

30. Nothing In or Out – Copy LAB Purpose: To discover if mass will change when conducting an experiment in a closed system. Results: – Mass of all objects before reaction ________g – Mass of all objects after reaction __________g – Mass of flask and balloon after opening ________g Questions: 1.Why is this experiment conducted in a “closed” system? 2.Did the mass change before the balloon was removed? Why? 3.Did the mass change after the balloon was removed? Why? Conclusion:

31. Chemical Reaction : Baking Soda & Vinegar CH 3 COOH + NaHCO 3 H 2 O + NaOCOCH 3 + CO 2 Vinegar Baking Soda Water Sodium Carbon Acetate Dioxide ELEMENTS C H O Na ELEMENTS C H O Na ATOMS C 3 H 5 O 5 Na 1 ATOMS C 3 H 5 O 5 Na 1

32. Open System Closed System Chemical Reaction where matter is allowed to enter or escape therefore the mass will change. Chemical Reaction where matter cannot enter or escape therefore the mass will stay the same.