Name _________________________________________________ Date _________ Period ___________
1st Semester Review
CHEMISTRY
1. Complete the chart below.
How much mass do they
contain?
Electron
Protons
Neutrons
Very little
1 AMU
(most of the mass)
1 AMU
(most of the mass)
Nucleus
Nucleus
Positive
Neutral, no charge
Energy levels / electron
cloud
Negative
Location
Charge
2. Use the Periodic Table to fill in the chart below:
ELEMENT
SYMBOL
ATOMIC #
ATOMIC
MASS
PROTONS
NEUTRONS
ELECTRONS
GROUP
#
# OF V
ELECTRONS
PERIOD
#
Boron
Phosphorus
Potassium
B
P
K
5
15
19
11
31
39
5
15
19
6
16
20
5
15
19
13
15
1
3
5
-
2
3
4
3.
9
F
Draw a Bohr Model atom of Fluorine. Label the Protons, Neutrons, and
Electrons and identify charges. What makes this atom NEUTRAL? (think
about the subatomic particles)
Protons = positive
18.998
Electrons = negative
P=9
Neutrons = neutral (no charge)
N = 10
Atoms are neutral because they share the same number of protons and electrons. Since protons are
positive and electrons are negative… their charges cancel each other out, so they are neutral.
Which subatomic particle identifies the atom? Protons What subatomic particle is most important
when determining an element’s chemical properties? Valence Electrons
4. Without drawing an atom, how can we tell how many rings we’ll need, how many Valence electrons it
will have, and with what element it shares its properties with?
The period number tells you the number of rings
Look at the group number for the number of valence electrons. Group 1 has one valence electron;
group 2 has 2 valence electrons. For groups 13-18 (3A – 8A), look at the last number of the group to tell
you how many valence electrons it has. Remember, think of the “A” as an upside down “V” for valence
Each group shares similar properties.
5. All members of the same Group/Family will have the same chemical properties! Why?
They have the same number of valence electrons.
6. Name three atoms that would have similar characteristics as Argon. Why do they have similar
characteristics?
Helium, Neon, Krypton, Xenon, and Radon. They are all in the same group, so the all share the same
number of valence electrons.
7. Which metal family is most reactive – WHY? Which non-metal family is most reactive – WHY?
Group 1 is the most reactive metal group because they are 1 away from being happy/stable
Group 7A is the most reactive non-metal group because they are also 1 away from being happy/stable
8. Which family is least reactive – WHY?
Group 8A (THE NOBEL GASES) is the least reactive because it has a full outer energy level.
9. Draw a rough sketch of the periodic table. Label where the metals, metalloids, and non-metals are.
Orange = non metals
Blue = metals
Purple = metalloids
10. Describe the 4 clues that a chemical reaction has taken place.
Temperature change, color change, gas formation, and precipitate (solid formation)
11. Describe the Law of Conservation of Mass.
Matter can neither be created nor destroyed, it can only change forms
12. Using the Law above, how would you complete the equation below?
(5 grams) Salt + ____5___ Sodium  (10 grams) Sodium Chloride
13. How many atoms are in the following compounds?
H2O = 3
5 CO2 = 15
H2SO4 = 7
14. How many elements are in the following compound? 5Al2O3 2 Elements (Al and O)
15. How many atoms of Al are in the previous compound? 10
16. 6CO2 + 6H2O + Energy  C6H12O6 + 6O2
a. What is reacting? Carbon dioxide and water (left side) – they are the reactants
b. What are two final products? Glucose and oxygen (right side) – they are the products
16. Identify the following equation as balanced and unbalanced.
a. P4+5O2 → P4O10 = balanced
P=4
P=4
O = 10
O = 10
b. Zn +O2 → ZnO = unbalanced
Zn = 1
Zn = 1
O=2
O=1
c. SiCl4 → Si + 2Cl2 = balanced
Si = 1
Si = 1
Cl = 4
Cl = 4
d. H2O2 →
H2O+O2 = unbalanced
H=2
H =2
O=2
O=3
17. Which of the following are compounds and which are elements? SO – compound, Al – Element, Na –
Element, CO2 – Compound, NaCl - Compound
18. The process by which one or more substances change into one or more new substances is called a
Chemical Reaction.
19. Describe the difference between a covalent and ionic bond.
Covalent Bonds – share valence electrons in order to be stable/happy. Bonds between a non-metal and
a non-metal
Ionic Bonds – transfer valence electrons in order to be stable/happy. Bonds between a metal and a nonmetal
20. If my lunch is digesting, is this a physical or chemical change? Chemical
21. If I tear a piece of paper in ½, is this a physical or chemical change? Physical
22. An object has a mass of 75 g. In a graduated cylinder the volume goes from the 50 ml line to the 75
ml line when the object is added to water. What is the density of the object?
M = 75 g
V = 75 ml – 50 ml = 25 ml
D=?
75 g / 25 ml = 3 g/ml
23. The mass of an object is 174 g and the density is 3 g/cm3. Determine the volume of the object.
M = 174 g
V=?
D = 3 g/cm3
174 g / 3 g/cm3 = 58 cm3