Unit 1 Project
Developing a Chemistry Newsletter
Student Textbook pages 152–153
This performance task provides an excellent opportunity for students to learn about the
safe use of household chemicals in everyday life, and to demonstrate their
communication skills by presenting what they have learned in the form of a newsletter.
Students will have a chance to experience first-hand the challenges faced by scientists as
they try to communicate important chemical information to the public. Through this
performance task, students will begin to recognize the importance of achieving excellence
in scientific literacy.
Many students will be tempted to carry out all of their research on the Internet.
Encourage students to do research “in the field” by gleaning information from products
found in their own homes and in hardware and grocery stores.
Students have an opportunity to flex their creative muscles with this performance
task. Suggest to artistic students that they create comic strips or visual organizers to add
interest to the newsletter. Students who like to write may enjoy creating fictitious
scenarios or news items to illustrate safe and unsafe use of household chemicals. While
the scenarios and comic strips can be imaginary or fanciful, the safety and chemical
information contained within them must be factual, and the purpose clear.
Students may balk at the idea of interviewing a professional. Although experts are
often more willing to help when contacted over the phone or by mail, students can send
a questionnaire via e-mail. It is relatively easy to search for experts on the Web. You may
want to go over students’ planned list of questions with them before they approach an
expert.
Assessment and Evaluation
Performance
Task
Curriculum
Expectations
Assessment
Tools/Techniques
Achievement
Chart Category
Learning Skills
Unit 1 Project:
Developing a
Chemistry
Newsletter
■
■
■
■
■
[MCB V.03] describe how an understanding of
matter and its properties can lead to the
production of useful substances and new
technologies
[MCB 3.04] demonstrate an understanding of
the need for the safe use of chemicals in
everyday life (e.g. cleaners in the home,
pesticides in the garden)
■
Studentdesigned rubric
for
self-assessment:
Rubric for Unit 1
Project (see
“Assessment
and Evaluation”
in the front
matter of
Teacher's
Resource
CD-ROM)
■
Making
Connections
Inquiry
■
■
Teamwork
Initiative
Organization
Unit 1 Review Answers
Student Textbook pages 154 –157
Answers to Knowledge/Understanding Questions
1. (c)
2. (c)
3. (e)
Unit 1 Matter and Chemical Bonding • MHR
157
4. (d)
5. (b)
6. (a)
7. (c)
8. (b)
9. (a)
10. (a)
11. (c)
12. (d)
13. False — this scale is precise, but not accurate.
14. True
15. False — matter is anything that has mass and occupies space.
16. False — the three standard states of matter that exist at room temperature are solid,
17.
18.
19.
20.
21.
22.
23.
24.
25.
liquid, and gas.
False — when iron rusts, elements becomes a compound. This is a chemical change.
False — acid rain is a solution.
False — when water melts, a physical change occurs.
False — to change water from ice to liquid - energy must be added to the water.
False — a gold ring is an alloy of gold, which is a homogenous mixture.
False — water is an example of a compound.
True
True
False — the number of particles, such as molecules, may be different, but the number
of atoms of each element is the same.
Answers to Short Answer Questions
26. Examples of everday reactions include iron rusting, food cooking, plants growing,
and food digesting.
27. In a cylinder of pure nitrogen gas, you would find nitrogen–14 and nitrogen–15
— two different types of atoms.
28. (a) K, Na, H
(b) Mg, Si, S
(c) K, Cl, Ar
29. (a) B, N, F
(b) Br, Cl, F
(c) Cs, K, Na
30. (a) Ca, Mg, Be
(b) Se, Br, Kr
(c) Cs, K, Na
31. (a) ammonium nitrate
(b) lead(IV) acetate
(c) Disulfur dichloride
(d) barium nitrite
(e) tetraphosphorus decaoxide
(f) manganese(III) oxide
32. (a) SrCl2
(b) PbSO3
(c) Cr(CH3COO)3
(d) H2S
(e) IF7
158
MHR • Unit 1 Matter and Chemical Bonding
33. Classification allows better understanding of the reactions, simplifies the nature of
each reaction, can generalize each reaction type for better understanding and
explanation.
34. (a) Zn(s) + 2AgNO3(aq) → Zn(NO3)2(aq) + 2Ag(s) , single displacement
(b) balanced, synthesis
(c) 2KClO3(s) → 2KCl(s) + 3O2(g) , decomposition
(d) balanced, double displacement
(e) 2C2H6O6(l) + 7O2(g) → 4CO2(g) + 6H2O(g) , combustion
35. (a) Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq) , single displacement
(b) 2HgO(s) → 2Hg(l) + O2(g) , decomposition
(c) 4Al(s) + 3O2(g) → 2Al2O3(s) , synthesis/combustion
(d) C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O(g) , combustion
(e) BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq) , double displacement
Answers to Inquiry Questions
36. Students should state the properties they are testing for. It is trivial to test for many
qualitative properties; physical state at room temperature and colour can be described
just by looking at the sample. Students may come up with interesting ways to test for
malleability, ductility, hardness, and brittleness. Quantitative properties that are fairly
straightforward to test for are density, solubility, and electrical conductivity. Ensure
that students provide a detailed procedure that addresses safety and includes controls
where appropriate.
37. Students should use Investigation 4-A as a model. They should note that the
production of hydrogen gas indicates that a reaction has taken place.
38. In Trial #1 the mass of paper and powder should be reported to 2 decimal places. In
Trial #2 the mass of filter paper should be reported to 2 decimal places. Also, the
mass of calcium sulfate should be 8.61 g according to the data. In Trial #3 the mass
of calcium sulfate should be reported to 2 decimal places.
39. Students’ procedures will probably include tests to compare the several different
properties of metals and non-metals. For example, metals tend to be are ductile and
malleable solids, while non-metals tend to be gases, liquids, or brittle or crystalline
solids. Solid metals tend to conduct electricity, while non-metal solids do not.
Students may also propose carrying out various reactions to test the reactivity of the
unknown substances with reactants such as acids. Accept all reasoned and reasonable
answers, and ensure students have included safety considerations in their procedures.
40. (a) Based on appearance, the compound could be either ionic or covalent.
(b) Both salt-like crystals (NaCl) and sugar-like crystals fit the description of the
compound.
(c) Students’ procedures could include testing for the melting point of the unknown
compound and for the conductivity of a solution of the unknown compound.
41. (a) The reaction is a single displacement reaction, in which metal X is displacing
metal Z.
(b) X is more reactive since it is displacing Z from its compound.
(c) Possible combinations of substances that would behave like metal X and
compound ZSO4 are: zinc metal and copper(II) sulfate, magnesium metal and
zinc sulfate.
Unit 1 Matter and Chemical Bonding • MHR
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Answers to Communication Questions
21.5 g
58 cm3
19.3 kg/dm3
17.5 g
298
43. Group 1 – alkali metals – soft, gray metals, react with water to produce hydrogen gas
Group 2 – alkaline earth metals – gray metals, some react with water
Group 17 – halogens – tend to exist as diatomic molecules
Group 18 – noble gases – very non-reactive
42. (a)
(b)
(c)
(d)
(e)
44.
Atom or ion with mass number
Number of protons
Number of neutrons
Number of electrons
14 3−
N
7
7
10
16 2−
S
16
16
18
He
2
2
2
7 +
3
4
2
20
20
18
4
Li
40
2+
Ca
45. (a)
(d)
Ar
B
(b)
Na
(c)
Al
(e)
Al
(f)
B
46. (a)
C
(b)
N
(c)
O
(d)
F
(e)
Cl
(f)
Br
Pattern 1: Number of valence shell electrons increase across a period (row).
Pattern 2: Number of valence shell electrons stays the same down a group (column).
47. Atomic radius increases going down the periodic table and decreases going across the
periodic table.
Ionization energy decreases going down the periodic table and increases going across
the periodic table.
Electron affinity decreases going down the periodic table and increases going across
the periodic table.
48.
49. (a)
(d)
50. (a)
(b)
(c)
(d)
(e)
160
Chemical Properties
Physical Qualitative Properties
Physical Quantitative Properties
Reactivity with acids
Colour
Melting point
Flammability
Malleability
Density
Reactivity with air
Hardness
Electrical conductivity
Toxicity
Brittleness
Boiling point
Br Cr Br
(b)
H S H
H As H
C S
(e) S
H
A + B → AB
XY → X + Y
compound or element + O2 → oxides
M + RX → R + MX
AB + CD → AD + CB
MHR • Unit 1 Matter and Chemical Bonding
(c)
Cl
Cl C Cl
Cl
51. Because nitrogen, phosphorus, and arsenic are all in the same group, students will
assume their hydrogen compounds have the same shape. Students know that
ammonia is a polar molecule. The bonds in phosphine and arsine, however, have very
small electronegativity values, so the molecules will be almost non-polar. Therefore,
you would expect phosphine and arsine to have lower boiling points than ammonia,
since the intermolecular forces due to dipole attractions would be significantly
weaker. (Arsine has a boiling point of –55˚C, phosphine has a boiling point of
–88˚C, and ammonia has a boiling point of –33˚C)
52. The molecule BF3 is trigonal planar (you will probably need to give students this
information). Because the polar bonds balance each other, the molecule is non-polar.
Answers to Making Connections Questions
53. Students will probably work with the idea that a defense lawyer tries to establish
reasonable doubt when arguing a case. If expert witnesses for the prosecution provide
scientific evidence that can be shown to have a significant degree of uncertainty, the
evidence will be effectively worthless to the prosecution. The argument can work the
other way, of course. If counterevidence is provided by the defense, the prosecution
will try to find out whether the science behind it is inaccurate, is incomplete, or has a
significant margin of error.
54. In ancient times, the known metals were the least reactive ones that occurred
naturally (such as silver), or were easily extracted from their ores (such as iron). The
most reactive metals were unknown since no extraction methods were known to
decompose their compounds. Theories of matter at the time did not predict new
metals so no one was looking for them.
Unit 1 Matter and Chemical Bonding • MHR
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