Review Questions:
Chap 1: Atoms and Periodic Table
1.
Associate each of the scientist/philosophers in the left column to their input (right
column) in the evolution of the atom.
1. Dalton
2. Democritus
3. Thomson
4. Bohr
5. Chadwick
6. Rutherford
a) Original idea of the atom
b) Electrons flowed on distinct electron shells
c) Neutrons hold the protons together
d) Atoms are different sizes for different elements
e) Atoms are made mostly of empty space
f) Electrons are negatively charged particles in
positive “dough”
2. Draw a Rutherford-Bohr atomic model for each of the following elements.
a) I am the first element in
b) I am an alkali metal with
the group of alkali metals.
three electron shells.
c) I am a halogen with one
electron shell more than
fluorine.
3. Draw a Lewis structure and simplified model for each of the following elements.
Remember to write the names of the elements.
a) I am a noble gas belonging b) I am the lightest halogen. c) I am the smallest of the
to the third period.
atoms with four valence
electrons.
4. In order to find the amount of neutrons in a substance, we round the
to the nearest unit and subtract the
.
5. The chemical reactivity of a substance (how it reacts) is based on its
6. Where in the periodic table can you find the following:
a) an alkaline earth metal?
b) a noble gas?
c) a halogen?
d) a metal?
e) an atom containing only one
electron shell?
7. What is the ionic charge of the following atoms?
Fluorine
Beryllium
Calcium
Aluminum
Sodium
8. Using the chart below, answer the following two questions.
A.
If I want Gold and Plastic to attract each other, what two substances
should I rub together?
B.
If I rub gold and cotton together and then rub paper and sulfur together,
what will happen when I bring the gold and the sulfur together?
Tendency to have
a negative charge
Tendency to have
a positive charge
Plastic
Gold
Sulfur
Cotton
Paper
Wool
.
9. What happens to the charges of the objects after the following charging methods were
used?
Friction
Conduction
Induction
10. Based on the following diagrams, what would occur if A and E (positive) were placed
side by side?
A
B
B
C
E
D
D
C
11. Based on the following diagrams, what would be the charge for the objects A, B, C
and D if E is negatively charged?
A
C
D E
D
A
A
B
12.
How many grams of salt will be created if I mix 72g of sodium with 80g of
chlorine?
13.
If I wanted to create 90g of water, how many g of oxygen do I need to
combine with 10g of Hydrogen?
14. You are given a quantity of NaOH that you wish to neutralize. Which of the
following would you use (HCl, H2O or NaCl) and write down the procedure
you will use?
15. The following substances will react to which color litmus paper
– NaOH
– HF
– CH3COOH
16. Balance the following equations:
a. (NH4)2Cr2O7 → N2 + H2O + Cr2O3
b. Fe + O2 → Fe2O3
c. N2 + H2 → NH3
17. Identify the chemical changes in the following list, and for each change, write at least
one sign that justifies your choice.
a) A candle burns, making the wax melt.
b) Frost forms on a car windshield in winter.
c) Vinegar makes milk curdle.
d) Iron turns red when heated.
e) Wild strawberries ripen at the end of June.
f) Sugar crystals form in syrup that is too thick.
g) Baking powder makes a cake rise.
18. Which part of the triangle of fire are firefighters tackling in each of the following
situations? Explain your answers.
a) Firefighters at an airport pour foam onto a pool of flammable liquid spilled by an
airplane in distress.
b) Firefighters spray water onto the roofs and sides of two houses next to a blaze.
c) During a forest fire, firefighters begin clear-cutting a threatened area. They cut a
50-m-wide stretch of forest a few kilometres ahead of the fire.
19. What distinguishes photosynthesis from cellular respiration? Name at least five
differences.
Cellular respiration
Photosynthesis
20.
Other solutions, such as some medicines, are solids. According to the label on
a medication for cramps and headaches, for example, each tablet contains
60 mg of caffeine and 340 mg of another substance. What is the caffeine
content of each tablet, in % m/m?
21.
A 500-mL bottle of isopropyl alcohol, better known as rubbing alcohol,
contains 350 mL of alcohol. What is the alcohol concentration of this solution
in % V/V?
22.
Name the substances that act as solvents and solutes in each of the following
solutions.
Solution
Solvent
Solute
a) Air is composed of approximately
80 percent nitrogen and 20 percent
oxygen.
b) Steel is an alloy of iron with a small
amount of carbon.
c) Seawater contains many mineral salts.
23.
The water in a lake is contaminated. To determine the concentration of the
contaminant, a technician takes a 50-mL sample of the water. After several tests,
he concludes that the sample contains 3.75 mg of contaminant. Calculate the
concentration of the contaminant, in ppm.
24.
Draw the position of the needle in each of the compasses placed near the magnets
or wire illustrated below. Also draw the magnetic field lines for A and B.
a)
b)
N
N
S
S
Compass I
Compass II
–
+
c)
Compass III placed beneath the wire
25. Explain why the geographic North Pole is necessarily a magnetic south pole.