Name
CP Biology 2015-16
Date
Period
PRACTICE PACKET
UNIT 2A:
Basic Chemistry
HW #1: Periodic Table
Use the following terms to fill in the blanks for questions 1-8:
protons
mass number
neutrons
energy levels
nucleus
symbol
electrons
atomic number
1) The large letter(s) that represent each element is called a _______________________________.
2) The number of protons in the nucleus of an atom is the same as the a) ______________________, and
b) __________________________________.
3) The periodic table is arranged in general order of increasing a) ___________________________,
b) _____________________________
and, c) _______________________________.
4) Each element in the table has a different a) ______________________, b) ______________________,
c) ___________________________, and d) ____________________________.
Complete the diagram by labeling all the parts.
5)
6)
Made up of 7)
and 8)
9)
12) Complete the following table by placing a check in each box that makes the statement true:
Characteristic
Proton
Neutron
Electron
Does not have an electrical charge
Found in the nucleus
Positively charged
Moves in energy levels
Negatively charged
Has nearly no mass
Added together to make the mass number or
atomic mass (weight)
1
HW #2: Atomic Structure
You will become more familiar with the atomic structure of common elements by completing the chart below.
For each element, you have been given enough information to fill in all the blanks.
Element
Symbol
Atomic
Number
Mass
Number
Helium
He
2
4
Magnesium
Mg
12
Zinc
Zn
30
Bromine
Br
Aluminum
Al
Uranium
U
Sodium
Na
Krypton
Kr
Calcium
Ca
Silver
Ag
Number of
Protons
Numbers of
Neutrons
Number of
Electrons
2
12
65
35
80
45
13
14
146
11
35
92
12
48
40
20
20
47
61
36
2
HW #3: Reactivity of Atoms (use your Notes Packet as a Word Bank)
In biology we are concerned about how atoms join each other to form molecules like hydrogen gas (H2),
carbon dioxide (CO2) and glucose (C6H12O6). The tendency of atoms to bond with each other depends on
how _PROACTIVE / REACTIVE__ they are.
The reactivity or bonding ability of an atom depends upon the arrangement of electrons in the outermost
energy levels.
1. If the outermost energy level is completely filled with electrons (no vacancies), the atom is said to be
______________and ________________. It ( will / will not ) combine with other elements.
Examples _______________________________________________________________
2. If the outermost level is not completely filled with electrons(vacancies are present), the atom is
considered ____________________ and __________________. It ( will / will not ) combine with
other elements.
Examples of reactive atoms:
Element
Symbol
Hydrogen
H
Aluminum
Al
Carbon
C
Sodium
Na
Neon
Ne
Oxygen
O
Nitrogen
N
Phosphorus
P
Atomic
Number
# electrons
# of
electrons in
valence
level
# of
vacancies
in the
valence
level
Reactive
(R) or nonreactive
(NR)
List the most common elements in living things:_______, ________, ________, ________, _________
Are these elements reactive or non-reactive? __________________
3
HW #4: Electrons and the Reactivity of Atoms
Directions: Place the answer to the following questions on the line provided.
______1. Energy levels are:
a. the definite locations of electrons
b. the charge of atoms
c. the charge of protons
d. the probably locations of electrons
______2. If an atom is reactive, how does it become stable?
a. join a water molecule
b. form bonds with other reactive atoms
c. form energy levels with other subatomic particles
d. join the nuclei of other atoms.
Directions: Smiley Cyrus was a student at Livingston High School. Below are her drawings of
different atoms. Check Smiley Cyrus’s atoms and correct any mistakes that she made.
* P=protons
N=neutrons
Aluminum
E= Electrons
Potassium
13 P
14 E
= electrons in energy levels
Lithium
20 P
20 N
3E
7N
Circle the atoms below that are reactive.
Al
K
Li
How many electrons will the following need to be stable? Write the number on the line provided.
Al ________
K ________
Li ________
4
HW #5: Bonding Patterns
1) Is one atom of carbon stable?__________________ Why or why not?____________________________
_______________________________________________________________________________________
2) What is the purpose of bonding? __________________________________________________________
________________________________________________________________________________________
3) How many electrons will an atom of carbon share with another atom in order to become stable? ________
4) List three different types of bonds that can form between atoms?
a)__________________________, b) ______________________ and c) ________________________
5) A _________________________shows the types and numbers of atoms in a compound. For example,
H2O indicates that one molecule of oxygen has formed with two molecules of hydrogen.
The __________________ indicates how many atoms of the preceding element are needed in the final
molecule.
A ______________ indicates how many molecules of each compound are present. In order to determine the
number of atoms in a formula with a coefficient, multiply the coefficient by the ______________. When the
coefficient for a molecule is not indicated, that coefficient is the number one (example: CO2 indicates one
molecule of carbon dioxide). When the subscript for an atom is not indicated, that subscript is the number one
(example: the O in H2O).
Complete in the following chart:
Chemical Formula
H2O
CaCO3
3H2O
4H2SO4
Numbers and types of atoms in the compound
Two hydrogen atoms and one oxygen atom.
Directions for drawing structural formulas:
A structural formula is a drawing of the atoms in a compound and the number of bonds between atoms. The
short lines in a structural formula represent a bond that has formed between two atoms. A single bond is
represented by a single line (-). A double bond is shown with two lines (=). A triple bond would contain 3 lines
().
Example H2O or water :
In one water molecule, there ___ atom(s) of hydrogen and ____ atom(s) of oxygen.
H=Hydrogen—Has one electron and one vacancy in the first energy level. So, it needs ___ bond(s) to be
stable.
O=Oxygen—Has 2 electrons in the first level and 6 in the second level. So, it needs ___ bond(s) to be stable.
The only way to represent this is to draw:
H
O
H
In this way, the two atoms of hydrogen are bonded with
one atom of oxygen. The hydrogen atoms each have
one bond and the oxygen atom has two bonds.
5
Try these examples:
Draw the structural formulas for the following compounds:
H2
CH4
# bonds needed by hydrogen? _____1______
# bonds needed by carbon? _______ hydrogen? _____
H
H
O2
# bonds needed by oxygen? _________
HCl
# bonds needed by hydrogen? ________ Cl? ________
N2
# bonds needed by nitrogen _________
PCl3
# bonds needed by phosphorus? _______ Cl?_______
HCN (Hydrogen cyanide)
H2O
6
HW #6 Counting Atoms
Calculate how many atoms of each element are present in the following compounds.
1. NaHCO3
2. C2H4O2
i
¡
3. 3H3 PO4
4. 2H2SO4
5. C6H12O6
6. 4CaCO3
***7. Mg(OH)2
:
***8. (NH4)3PO4
7
HW #7: Recognizing Balanced Equations
EQUATION
A.
H2 + O2 --> H2O2
B.
H2O2 --> H2O + O2
C.
4Na + O2 --> 2Na2O
D.
N2 + H2 --> NH3
E.
P4 + O2 --> P4O10
F.
Fe + H2O --> Fe3O4 + H2
G.
C + 2H2 --> CH4
H.
I.
J.
BALANCED?
(Y/N)
Na2SO4 + CaCl2 --> CaSO4 + NaCl
C2H6 + O2 --> CO2 + H2O
2Al2O3 --> 4Al + 3O2
7
HW #8: Balancing Equations
Answer the following questions. Use complete sentences when given one or more lines to respond.
1) What is the difference between reactants and products in a chemical equation?
_______________________________________________________________________________________
_______________________________________________________________________________________
2) Which number indicates the number of atoms of each element in a molecule of a substance?
_______________________________________________________________________________________
3) Which number indicates the number of molecules?
_______________________________________________________________________________________
4) Why must chemical equations always balance?
_______________________________________________________________________________________
_______________________________________________________________________________________
5) Based on the Law of Conservation of Matter, which of the following equations is balanced?

Put a check on the line provided if the equation is balanced.

Extension: If the equation is NOT balanced, then rewrite a correctly balanced equation below it.
_______ a)
H2 + Cl2  2HCl
_______ b)
2H2O2  2H2O + O2
_______ c)
N2 + H2  NH3
_______ d)
Fe + 3O2  Fe2O3
_______ e)
C6H12O6 + O2  CO2 + H2O
8
Protons
Atomic Number
Electrons
Neutrons
ATOM
Mass Number
Symbol
Covalent Bond
Valence Electrons
Octet Rule
Molecule
10