CP BiologyNameDatePeriod
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 a neutral atom is the same as the a) ______, andb) ______.
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)
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 / Number of Protons / Numbers of Neutrons / Number of ElectronsHelium / He / 2 / 4 / 2
Magnesium / Mg / 12 / 12
Zinc / Zn / 30 / 65 / 35
Bromine / Br / 80 / 45 / 35
Aluminum / Al / 13 / 14
Uranium / U / 146 / 92
Sodium / Na / 11 / 12
Krypton / Kr / 48 / 36
Calcium / Ca / 40 / 20 / 20
Silver / Ag / 47 / 61
HW #3 Counting Atoms
Calculate how many atoms of each element are present in the following compounds.
1. NaHCO3
2. C2H4O2
:3. Mg(OH)2
i
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4. 3H3 PO4
5. 2H2SO4
6. (NH4)3PO4
7. C6H12O6
8. 4CaCO3
HW #4: Reactivity of Atoms
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 their ______.
The reactivity or combining capacity of an atom depends upon the arrangement of electrons in the outermost energy levels.
- 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 ______
- If the outermost level is not completely filled with electrons(vacancies present), the atom is considered ______and ______. It ( will / will not ) combine with other elements.
Examples of reactive atoms:
Element / Symbol / Atomic Number / # electrons / # of electrons in valence level / # of vacancies in the valence level / Reactive (R) or non-reactive (NR)Hydrogen / H
Aluminum / Al
Carbon / C
Sodium / Na
Neon / Ne
Oxygen / O
Nitrogen / N
Phosphorus / P
List the most common elements in living things:______, ______, ______, ______, ______
Are these elements reactive or non-reactive? ______
HW #6: 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 c. the charge of protons
b. the charge of atoms 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=protonsN=neutronsE= Electrons = electrons in energy levels
AluminumPotassiumLithium
Circle the atoms below that are reactive.
AlKLi
How many electrons will the following need to be stable? Write the number on the line provided.
Al ______K ______Li ______
HW #7: Covalent Bonding: Sharing is Caring
PART 1: What element have you been assigned?______
Draw a Bohr Model and Lewis Dot Structure for your Element:
Bohr/ Lewis Dot
- How many electrons are in the outermost (valence) electron orbit (shell)?______
Draw these in with open circles.
- How many “empty” spaces are there in the valence shell?______
- When an atoms outer shell is not “full” (8 electrons in most cases) it is not stable. (like a dining room table with only three legs).
How many electrons would your element need in order to be stable or unreactive?______
- How do you think an atom could become stable (think about interactions with other atoms)?______
PART 2: Draw the Bohr models of other atoms as they are discussed in class.
NAME:______Open Spaces:______/ NAME:______
Open Spaces:______/ NAME:______
Open Spaces:______/ NAME:______
Open Spaces:______
HW #7: 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 carbonshare 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 thecoefficient for a moleculeis 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 / Numbers and types of atoms in the compoundH2O / Two hydrogen atoms and one oxygen atom.
CaCO3
3H2O
4H2SO4
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.Try these examples:
Draw the structural formulas for the following compounds:
H2# bonds needed by hydrogen? _____1______
H H / CH4
# bonds needed by carbon? ______hydrogen? _____
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
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
HW #9: Recognizing Balanced Equations
What is the Law of Conservation of Matter?______
______
EQUATION / BALANCED? (Y/N)A. / H2 + O2 --> H2O2
B. / H2O2 --> H20 + O2
C. / 4Na + O2 --> 2Na2O
D. / N2 + H2 --> NH3
E. / P4 + O2 --> P4O10
F. / Fe + H2O --> Fe3O4 + H2
G. / C + 2H2 --> CH4
H. / Na2SO4 + CaCl2 --> CaSO4 + NaCl
I. / C2H6 + O2 --> CO2 + H2O
J. / 2Al2O3 --> 4Al + 3O2