November 13, 2012
Competency
2a
8th – Lesson 1.6
Name: ____________________________________ Period: ____
Identify patterns found in chemical symbols, formulas, reactions, and
equations that apply to the law of conservation of mass. (DOK 1)
I can describe molecules and how they are written using chemical
symbols.
Unit 4 – Chemistry: Molecules and Chemical Formulas
Daily Question: When chemists are working, what is the language they use and
how do they stay organized?
Key Points on Molecules and Chemical Formulas:
1. A group of at least two atoms bonded together = molecule
a. The atoms bonded together can be the same atom or different atoms.
2. A way of showing the types and number of elements in a molecule = chemical
formula
3. Each different atom in a molecule is shown with its chemical symbol from the periodic
table.
a. NaCl and HF are chemical formulas.
4. In a chemical formula, the number of atoms of each type in a single molecule is
shown with subscripts (numbers shown after each element).
a. If only one atom of that type is found in a molecule, the 1 is omitted (left out).
The chemical formula for table salt is NaCl not Na1Cl1.
b. For example, with MgSO4, there is one atom of Mg (magnesium), one atom of S
(sulfur) and four atoms of O (oxygen) in EACH molecule.
5. Sometimes a regularly sized number (the coefficient) is shown in front of the molecule
such as 2HNO3. This means that there are a total of two molecules of HNO3.
a. For example, caffeine has a chemical formula of C8H12N4O3. If a scientist is
describing three molecules of caffeine, it would be written at 3C8H12N4O3.
6. By multiplying the coefficient by the subscripts, we can determine the total number of
each type of atom.
a. In 4H2O2, there are four different molecules with a total of eight hydrogen atoms
and eight oxygen atoms.
List the different types of atoms in the
molecule
List the total number of each type of atoms in
the molecule
1. CH4 -
6. O3 -
2. Fe2O3 -
7. C6H12O6 -
atoms of oxygen
carbon,
hydrogen,
3. CaOH 4. H2SO4 -
8. 4N2O -
5. CH3Cl -
9. 6CO2 10. 3H3PO4 -
nitrogen,
oxygen
November 13, 2012
Name: ____________________________________ Period: ____
Competency
2a
Identify patterns found in chemical symbols, formulas, reactions,
and equations that apply to the law of conservation of mass. (DOK
1)
8th – Lesson 1.6
I can describe molecules and how they are written using chemical symbols.
Unit 4 – Chemistry: Molecules and Chemical Formulas
Key Points on Molecules and Chemical Formulas:
1. A group of atleast two atoms bonded together =
a. The atoms bonded together can be the
atom or
atoms.
2. A way of showing the types and number of elements in a molecule =
3. Each
atom in a molecule is shown with its
from the periodic table.
a. NaCl and HF are
.
4. In a chemical formula, the number of
of each type in a
molecule is shown with
(numbers shown
each
element).
a. If only one atom of that type is found in a molecule, the 1 is
(left
out). The chemical formula for table salt is
not Na1Cl1.
b. For example, with MgSO4, there is
atom of Mg (magnesium),
atom of S (sulfur) and
atoms of O (oxygen) in
molecule.
5. Sometimes a regularly
number (the
) is shown in
of the molecule such as
. This means that there are a
of
molecules of HNO3.
a. For example, caffeine has a chemical formula of C8H12N4O3. If a scientist is describing
three molecules of caffeine, it would be written at 3C8H12N4O3.
6. By
the
by the
, we can determine the
number of each type of atom.
a. In 4H2O2, there are four different molecules with a total of
hydrogen atoms
and
oxygen atoms.
List the different types of atoms in the molecule
List the total number of each type of atoms in the
molecule
1. CH4 6. O3 atoms of oxygen
2. Fe2O3 7. C6H12O6 - carbon,
hydrogen,
3. CaOH -
4. H2SO4 5. CH3Cl -
8. 4N2O -
nitrogen,
9. 6CO2 10. 3H3PO4 -
Unit 4 – Chemistry: Molecules and Chemical Formulas
Key Points on Chemical Reactions:
1. A process that causes chemical substances to change into other substances =
2. The chemical substances that are started out with =
oxygen
November 13, 2012
Name: ____________________________________ Period: ____
3. The chemical substances formed by the reaction =
4. A more simple explanation of a chemical reaction =
a. Chemical formulas of the reactants shown on the
b. Chemical formulas of the products shown on the
c. They are separated by an
(
)
d. The tip of the arrow points in the direction in which the reaction
e. The
of each reactant and product is shown in
i. (aq) – means the substance is dissolved in
ii. (s), (l), (g) – the substance is in the
,
5. All of the
of
contained in the
the
.
a. The idea that matter cannot be created or destroyed = the
of
.
, or
state
must also appear in
of
Chemical Reactions: Guided Practice
1.
2. What are the reactants in the chemical equation HBr + NaOH  NaBr + H2O?
3. What are the products in the chemical equation HBr + NaOH  NaBr + H2O?
4. List the products and their state in the chemical equation
NaCl(aq) + AgNO3(aq)  NaNO3(aq) + AgCl(s)
5. Is the following chemical equation CH4 + 2 O2  CO2 + 2O2 written correctly?
November 13, 2012
Name: ____________________________________ Period: ____
Molecules and Chemical Formulas: Independent Practice
Directions: Write like you are a successful person using professional language and complete
sentences.
1. Key Point #1: What is a molecule?
2. Key Point #2: What is a chemical formula?
3. Key Point #3: How are the atoms of a molecule shown in a chemical formula?
4. Key Point #4: How is the number of each type of atom in a molecule shown? For example, how
would you show that there are 2 hydrogen atoms in a water molecule?
5. Key Point #5: How would a scientist show that she has three molecules of carbonic acid (H2CO3)?
6. Key Point #6: If a molecule has a coefficient, how can you determine the total number of each
type of atom in all the molecules?
7. Directions: Put a check mark next to the correctly shown chemical formulas. Put an x next to the
incorrect chemical formulas and correct them.
a.
- H20
b.
- Ca1OH
c.
- H2SO4
d.
- 4C6H12O6
e.
- O2
f.
- 42N
g.
- H1Cl1
h.
- 6CO2
8. Directions: Give the total number of each different type of atoms in each molecule(s) below.
Make sure to list the full name of each atom using your periodic table.
a. NH3 –
nitrogen atom and
c. 6CO2 -
hydrogen atoms
b. C6H12O6 -
d. 2Fe2O3 -