Monday February 11, 2013
Daily Goals
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I can identify and explain the difference between an atom, molecule, compound, and ion.
I can identify the difference between a cation and anion.
I can identify if an atom will likely participate in ionic or covalent bonding by the number
of valence electrons.
I can identify and explain the difference between an organic and inorganic molecule.
Notes: I can identify and explain the difference between an atom, molecule and compound.
Definition
Example
Atom
Molecule
Compound
Notes: I can identify and explain the difference between an atom and an ion.
Definition
Atom
Cation
Anion
Example
Label each of the following as an atom (A), molecule (M) and Compound (C).
Identify each as being a neutral atom, cation, or anion:
C
Na+1
O
K+1
N
H+
Cl-1
-1
I
Fe+2
Counting Atoms Worksheet
Directions for each problem
1) write down the different elements in each compound.
2) write down how many of that particular atom there are
3) how many atoms are there total in the compound.
Examples:
1) NaOH
Na - 1
O -1
H -1
3 total
2) 5 ZnSO4
Zn – 1 x 5 = 5
S–1x5=5
O – 4 x 5 = 20
3) 3 Cu2(SO4)2
Cu- 2 x 3 = 6
S–1x2x3=6
O – 4 x 2 x 3 = 24
30 total
36 total
1) NaOH
6) 4 HNO3
11) 4 Mg(OH)2
2) MgCl2
7) 4 Li2O
12) 2 NaOH
3) Li2SO4
8) 3 H2O
13) 4 Al 2(SO3)3
4) NaC2H3O2
9) 3 Al2O3
5) NH4Cl
10) 5 ZnSO4
14) 2 (NH4)3PO4
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I can identify if an atom will likely participate in ionic or covalent bonding by the number
of valence electrons.
Bonding
An atom will not react with other atoms when it outermost electron
Inert:
shell is completely full. Such an atom is described as being inert. An
atom will react with other atoms when its outermost electron shell is
only partially full. Such an atom is described as being reactive. Atoms
Reactive:
that have an almost empty outermost electron shell, as well as atoms
that have an almost full electron shell can become stable by losing
electrons or gaining electrons. When this happens the balance
Charged Atom:
between protons and electrons are unbalanced—and the atom
becomes charged. When an atom gains electrons it becomes more
negatively charged, called an anion. When an atom loses electrons it
Anion:
becomes more positively charged, called a cation. When two ions are
held together by a bond it is called an ionic bond.
When an atom has a partially full electron shell it can become stable
Cation:
by sharing electrons with another atom. Like two children tugging to
gain possession of a teddy bear, electrons in covalent bonds are pulled
in opposing directions by the nuclei of the atoms involved. If the
Ionic Bond
children are of equal strength—the teddy bear will remain stretched
between them—this is the definition of a non-polar covalent
bond—equal sharing of electrons between two atoms.
Non-Polar Covalent Bond:
In many molecules that form covalent bonds, one nucleus has a larger
positive charge than the other and therefore attracts electrons more
strongly. Just as a stronger child will be able to pull the teddy bear
closer to himself, so the electrons will spend more time near the
larger, more positive nucleus and less time near the smaller nucleus.
The larger atom thus takes on slight negative charge from the
proximity of the electron and the smaller atom acquires a slight
positive charge. This is a situation of a polar covalent bond.
Polar Covalent Bond:
Bonding:
Typically but not always….atoms that have 1, 2, 6 or 7 electrons in their valence shell will likely participate
in an ionic bond.
Typically but not always…atoms that have 3, 4, or 5 electrons in their valence shell will likely
participate in a covalent bond.
To Determine the Exact Bond using Electronegativity
If there is an electronegativity difference between the two atoms of:
Strength of Bond outside of water:
≥ 2 Ionic Bond (Strong Bond)
≥ .5 to < 2 Polar Covalent (Medium Bond)
0- < .5 Non-Polar Covalent (Weak Bond)
Determining Ionic Bonds Using Valence Electrons:
Complete the Table:
Determine the number of each atom that will be needed to create an stable ionic bond. Then write
the formula for each compound produced:
Determining Covalent Bonds Using Valence Electrons:
Complete the Table:
Notes: I can identify and explain the difference between an organic and inorganic molecule.
Definition
Inorganic
Organic
Example
Tuesday February 12, 2013
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I can explain what the activation energy is in a chemical reaction.
I can identify and explain the difference between an endothermic and exothermic
chemical reaction.
I can identify and label the activation energy diagram for an endothermic and exothermic
reaction.
Notes: I can explain what the activation energy is in a chemical reaction.
Definition
Activation
Energy
Heat of Reaction
Reactants
Products
Endothermic
Exothermic
Example
1
Exothermic and endothermic reactions
Decide whether each of these reactions is exothermic or endothermic:
a) When two chemicals mix their temperature rises: _______________
b) A solid burns brightly and releases heat, light and sound: _______________
c) When two chemicals are mixed their temperature drops: _______________
d) Two chemicals will only react if you heat them continually: _______________
e) Plants take in light energy for photosynthesis: _______________
2
Making and breaking bonds
During chemical reactions the bonds between atoms break and new bonds form.
Energy must be absorbed to break a bond, so breaking bonds is endothermic.
Making new bonds is exothermic because energy is released.
a) When green copper carbonate decomposes, the equation is:
CuCO3
CuO
CO2
copper carbonate
copper oxide
carbon dioxide
Is the reaction exothermic or endothermic? Use ideas about bonds to explain why.
3
‘Make or break’
b) Most reactions involve bond breaking and bond making. This equation shows what happens
when methane (CH4) burns in oxygen (O2).
Mark the bonds broken in blue and the bonds formed in red.
c) Complete the table to show the number of bonds broken and formed:
Bonds broken
Number
Bonds formed
between carbon and
hydrogen
between carbon and
oxygen
between oxygen
atoms
between hydrogen
and oxygen
Number
d) Is the reaction exothermic or endothermic overall?
________________________________________________________________________
e) The overall energy change is decided by the strength of the bonds that are broken or formed
during the reaction. The stronger the bond the larger the energy change.
Which bonds must be stronger in this reaction – the bonds broken or the new bonds
formed?
________________________________________________________________________
energy
f)
An energy level diagram shows the energy taken in and released during the reaction. Add
the reactants, products and their separated atoms to the correct places on the diagram.
reactants
products
course of the reaction
Is the above reaction exothermic or endothermic?
How much energy is in the reactants?
How much energy is in the products?
How much energy does it take for the reaction to take place?
How much energy is stored or released during this reaction?
Is the above reaction exothermic or endothermic?
How much energy is in the reactants?
How much energy is in the products?
How much energy does it take for the reaction to take place?
How much energy is stored or released during this reaction?
Thursday February 14, 2013
 I can explain what entropy is and how synthesis and decomposition reactions can
increase or decrease entropy.
 I can analyze an activation energy diagram for endothermic, exothermic, synthesis,
decomposition and entropy.
 I can count the number of atoms and bonds in a molecule or compound to determine if
entropy is increasing or decreasing.
Definition
Entropy
Synthesis Rxn
Decomposition
Rxn
Example
For each of the following examples, determine if entropy is increasing or decreasing:
1. Hot water is moving towards cold water.
2. Separating jelly beans by color.
3. Not taking a bath for a week.
4. Not mowing your lawn.
5. Getting a hair cut.
6. Mixing ingredients to make cookies.
7. Majority of backpacks Rebecca sees on a daily basis.
8. A landfill.
9. Chiseling a sculpture
10. Putting herbicide on a weed.
11. Not watering your lawn.
12. Helping a hoarder clean their house.
Create an activation energy diagram to show the chemical reaction between glucose (C6H12O6)
and oxygen (O2) to create carbon dioxide (CO2) and water (H2O).
1. Determine if it is exothermic or endothermic reaction.
2. Determine if it a synthesis or decomposition reaction.
3. Show the reactants of the equation. Show the productions of the equation.
4. Show the number of atoms and bonds in the sugar, oxygen, carbon dioxide and water.
5. Indicate where entropy is decreasing or increasing.
Friday February 15, 2013
 I can identify and explain the difference between a covalent and ionic bond.
 I can identify the difference between a non-polar and polar-covalent bond
 I can identify the difference between a intermolecular and intramolecular bond.
'
Does it pass both vertical and horizontal symmetry test?
Notes: I can identify the difference between a intermolecular and intramolecular bond.
Definition
Intermolecular
Bond
Intramolecular
Bond
Hydrogen
Bond
Example