Name:_______KEY____________ Date:___________ Block:___
Biology 601 Chemistry Review Practice
1. Complete the following table
Chemical
Chemical
Number of
Name
Symbol
Protons
Hydrogen
1
Number of
total
electrons
1
Number of
valence
electrons
1
6
6
4
N
6
6
3
O
8
8
6
H
carbon
Lewis Dot
diagram
C
Nitrogen
Oxygen
2. What are valence electrons? WHY ARE THEY SO IMPORTANT?
-Valence electrons are electrons in the outer most shell of an atom.
-They are important because they are involving in bonding.
3. Complete the following table:
Molecule
Number of atoms molecule
contains
Molecular MassSHOW YOUR WORK
5
SHOW YOUR WORK
12 + (4*1) = 16
Methane (CH4)
8
Urea
(CN2H4O or NH2CONH2)8
SHOW YOUR WORK
12 + (14*2) + (1*4) + 16 = 60
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4. Compare and contrast the following intramolecular forces: ionic bonds, polar covalent
and nonpolar covalent bonds.
-Ionic Bond: Attraction between oppositely charged ions. Occurs between metals and
non-metals.
-Polar covalent bond: The electrons are shared between the two atoms. Polarity exist
because the two atoms has high electronegativity difference between them.
-Nonpolar covalent bond: The electrons are shared between the two atoms. Electrons are
equally shared between two atoms.
5. Define electronegativity.
-Electronegativity shows how much an atom “grabs” onto it’s electrons.
6. Using the periodic table, complete the following chart.
Bonded
Electronegativity
Bond type
(ionic, polar or nonpolar)
elements
difference
O-N
0.5
covalent
Show the polarity of the
bond by drawing an arrow
from the positive to
negative side on the bond
between the 2 elements
(i.e.  )
Towards O
K-Cl
2.8
ionic bond
Towards Cl
C- H
0.4
non-polar covalent bond
N/A
9. Label the picture of the water molecule below:
a. To show which elements have a slight + charge and which elements have a slight charge.
b. Draw more water molecules and use dashed lines to show the maximum number of
hydrogen bonds one water
molecule can make.
a. Hydrogens has slightly
positive and oxygen has slight
negative charge
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b.
7. Circle or highlight where the following molecule, Serine, is capable of making hydrogen
bonds.
Places capable for hydrogen Bonds: NH2, COOH, OH
8. What are the parts of a solution?
-The Solute: substance that is dissolved
-The Solvent: substance that solute can dissolve in.
9. What is solubility?
-a property that tells us how a substance can dissolve in a solvent.
10. Which salt solution is more concentrated, solution A, which contains 18g of salt in 6L of
water, or solution B, which contains 24g of salt in 12L of water?
-Solution A is more concentrated because there is more percentage of solute dissolved
in the solvent.
11. Define pH. Describe an acid and a base. Draw the pH scale, labeling neutral, acidic, and
basic regions.
-pH measures the acidity or basicity of an aqueous solution
-Acid examples: lemon juice, vinegar
Base example: blood, baking soda
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