1. MS – PS1 - 5
Conservation of Mass

2. CHEMISTRY Unit 1 - Day 11 Do Now:
OBJECTIVE(NGSS MS-PS1-5): Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved.
Do Now:
Element Identification and Word Search
Today:
Conservation of Mass Balancing Act packet
Do Later:
SIA articles or Any unfinished notebook pgs

3. Do Now: Today: Do Later: CHEMISTRY Unit 1 - Day 12
OBJECTIVE(NGSS MS-PS1-5): Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved.
Do Now:
Finish Balancing Reactions pg 4
Finish Element Word Search (find 20)
Today:
Review Balancing Reactions
LAB: Conservation of Mass Reaction in a Bag - PARTS A & B
Do Later:
SIA articles or Any unfinished notebook pgs

4. Do Now: Today: Do Later: CHEMISTRY Unit 1 - Day 13
OBJECTIVE(NGSS MS-PS1-5): Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved.
Do Now:
Elements and Compounds crossword
Today:
LAB: Conservation of Mass Reaction in a Bag –PART B & PART C
(if time) DVD Chemistry Field Trips
Do Later:
FINISH LAB QUESTIONS
SIA articles or Any unfinished notebook pgs

5. Do Now: Today: Do Later: CHEMISTRY Unit 1 - Day 14
OBJECTIVE(NGSS MS-PS1-5): Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved.
Do Now:
Any unfinished notebook pgs ?
NOTEBOOK check
Turn in Reaction in a Bag Lab
Today:
SIA Presentations
Greatest Chemical Discoveries
Do Later:
SIA articles or Any unfinished notebook pgs

6. Do Now: Today: Do Later: CHEMISTRY Unit 1 - Day 15
OBJECTIVE(NGSS MS-PS1-5): Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved.
Do Now:
Conservation of Mass Review Worksheet
Today:
Conservation of Mass Review
Review Lab and Balancing Equations
Finish SIA Presentations
Finish Greatest Chemical Discoveries
Do Later:
Any unfinished notebook pgs

7. Balancing Act

8. Chemical Reactions Review…
Is the process where physical and chemical properties of the original substance change into a new substance with different physical and chemical properties
If there is no new substance there has been no reaction
Reactants enter into the reaction
Products are produced by the reaction

9. Chemical Reactions Review…
Chemical equations describe chemical reactions using symbols and numbers.
2Na + SrCl2 ® Sr + 2NaCl
Coefficients (in red)
The large numbers in front of chemical formulas.
The number of molecules of the substance in the reaction

10. Chemical Reactions Review…
Chemical equations describe chemical reactions using symbols and numbers.
2Na + SrCl2 ® Sr + 2NaCl
Subscripts (in Green)
The small numbers to the lower right of chemical symbols
Represent the number of atoms of each element is in the molecule

11. Chemical Reactions Review…
Atoms can neither be created nor destroyed during a chemical reaction…Mass MUST remain constant
You have to end up with the same number of atoms you started with, but in a different arrangement
So balanced equations have the same number of atoms on each side of the YIELDS “®“ sign
Law of Conservation of Mass

12. Balancing Chemical Equations (ALWAYS USE PENCIL)
Check for DIATOMIC molecules H2 , N2 , O2 , F2 , Cl2 , Br2 , I2 , and At2
You cannot change the subscripts of these elements in an equation… whenever they are by themselves, these must be written with the subscript 2.

13. Balancing Chemical Equations
Count the number of atoms on each side of the reaction:
___Na + ___MgCl2 ® ___Mg + ___NaCl
Sodium=____ ® Sodium=____
Magnesium=____ ® Magnesium =____ Chlorine= ____ ® Chlorine=____ 1 2 1

14. Balancing Chemical Equations
Balance the metals first then the nonmetals
___Na + ___MgCl2 ® ___Mg + ___NaCl
Sodium=____ ® Sodium=____
Magnesium=____ ® Magnesium =____ Chlorine=____ ® Chlorine=____ 2 2 1 2
X 2 1
X 2
X 2

15. Balancing Chemical Equations
If they are in your equation, balance OXYGEN then HYDROGEN last
Recount all atoms and check your work!
Work from the bottom to top until you find any error.
If every coefficient will reduce, rewrite in the simplest whole number ratio

16. Balancing Chemical Equations
Lets try an easy one:
___H2 + ___O2 ® ___H2O
Hydrogen=____ ® Hydrogen=____
Oxygen=____ ® Oxygen =____ 2 2 2 1
X 4 2
X 4
X 2

17. Balancing Chemical Equations
Lets try one more:
___Na + ___HCl ® ___H2 + ___NaCl
Sodium=____ ® Sodium =____
Hydrogen=____ ® Hydrogen=____
Chlorine=____ ® Chlorine =____ 2 2 2 1
X 2 1 2
X 2
X 2
X 2
X 2

18. Balancing Act ___Mg + ___O2 ® ___MgO ___Ca + ___O2 ® ___CaO
___H2O2 ® ___H2O + ___O2
___N2 + ___H2 ® ___NH3
___Cu2O + ___C ® ___Cu+ ___CO2

19. Reaction in a Bag: PART A THE ORIGINAL REACTION
PART B CONTROLLED EXPERIMENTS
PART C CONSERVATION OF MASS