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I can observe and explain the Law of
Conservation of Mass.
I can ask scientific questions about
observations and formulate hypotheses.
I can interpret my observations from the lab
activity and compare them to my hypothesis.
I can write out chemical equations based on
demonstrations or lab experiments.
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I can explain why the demonstration had the
results that it did. (no change in mass)
I can state the purpose and for my lab
experiment and report.
I have answered whether or not my prediction
was correct and why or why not this is so.
I have written down the chemical and/or word
equation for the demonstration.
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I can use diagrams to show atoms and
molecules.
I can use diagrams to model chemical
reactions.
I can balance chemical equations and explain
why they are balanced.
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Mass CANNOT be created or destroyed.
In a chemical reaction, the total mass of the
reactants is ALWAYS the same as the total mass of
the products. This is the definition of the Law of
Conservation of Mass.
The number of each type of atom is the SAME
before and after a chemical reaction. The atoms of
the reactants are RE-ARRANGED to form the
products.
Molecules can be split apart to form new molecules
BUT the atoms in the products are the same atoms
that were in the reactants.
NEVER CHANGE THE CHEMICAL
FORMULA!!!
You can ONLY add coefficients!
3PO4
coefficient
chemical
formula
Step 1:
COUNT all the atoms on each side of the
equation. Break up polyatomic ions into
elements. Make a chart to record the number
of atoms present for each side of the
equation.
Step 2:
Always START balancing with the METALS, then
the non-metals. Leave oxygen and hydrogen
until the end.
Step 3:
Add a COEFFICIENT (big number) in front of the
chemical formula that needs to be balanced,
so that the number of atoms of each element
on the reactant side is the same as those on
the product side.
NOTE:
Each time you put a coefficient in the equation, you
must RECOUNT the atoms on both sides before you
continue to add any other coefficient.
Step 4:
CHECK that your equation is balanced when
you are finished.
Example
Na +
Reactants
Cl2
NaCl
Products
Example
Na +
Cl2
NaCl
Reactants
Products
Na
Na
Cl
Cl
Example
Na +
Cl2
NaCl
Reactants
Products
Na
1
Na
1
Cl
2
Cl
1
Example
Na +
Cl2
2NaCl
Reactants
Products
Na
1
Na
1
Cl
2
Cl
1
Example
Na +
Cl2
2NaCl
Reactants
Products
Na
1
Na
1
Cl
2
Cl
1
2
Example
Na +
Cl2
2NaCl
Reactants
Products
Na
1
Na
1
2
Cl
2
Cl
1
2
Example
2Na +
Cl2
2NaCl
Reactants
Products
Na
1
Na
1
2
Cl
2
Cl
1
2
Example
2Na +
Cl2
2NaCl
Reactants
Na
1
Cl
2
2
Products
Na
1
2
Cl
1
2
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I can create ionic and covalent bonding
diagrams/ I can create diagrams to show
balancing in chemical reactions.
I can look at a chemical equation and balance
it by changing the coefficients.