SNC1D – Science Grade 9
Unit 2 Test – Atoms, Elements and Compounds
Name:
INSTRUCTIONS
1. You have 3 hours to complete this test.
2. You must attempt all sections to be eligible for a score of 100%.
3. You will be assessed in four categories:
K: Knowledge and Understanding;
T: Thinking and Inquiry;
C: Communication;
A: Application.
4. For every question the necessary calculation and proving process is required
for score purpose.
5. The assessment categories are broken down and displayed for each questions,
as well as the overall test
Sections K T C A
A
B
C
TOTALS
Page 1 of 9
Part A: Multiple-Choice (2 marks each)
1. What warning does the WHMIS symbol shown below represent?
(a) corrosive substance
(b) combustible substance
(c) poisonous substance
(d) reactive substance
2. What types of matter are made up of only one kind of particle?
(a) compounds and solutions
(b) heterogenous mixtures and elements
(c) pure substances and mixtures
(d) elements and compounds
3. Which of the following statements describing the separation of matter is true?
(a) The components of a heterogenous mixture can be separated through physical methods.
(b) The components of a solution can be separated using filtration.
(c) The components can be broken down into simpler substances through chemical methods.
(d) A pure substance can be broken down only through physical methods.
4. Which of the following is a quantitative physical property?
(a) solubility
(b) odour
(c) lustre
(d) texture
5. Which of the following statements regarding the reactivity of metals is true?
(a) Metals that have fewer occupied energy levels are more reactive than metals with more
occupied energy levels.
(b) Metals become more reactive as their atoms get smaller.
(c) Metals become more reactive as you move from left to right across a period.
(d) Metals become more reactive as you move from top to bottom in a group.
Page 2 of 9
6. How many electrons does a neutral atom have if the mass number is 31 and the number of
neutrons is 16?
(a) 15
(b) 16
(c) 31
(d) 47
7. Which statement about forces within an atom is false?
(a) Protons and electrons attract one another due to electric charge.
(b) Protons and neutrons attract one another due to the strong force.
(c) Electrons and neutrons neither attract nor repel one another due to electric charge.
(d) Protons and electrons repel one another due to strong force.
8. What is the atomic number of aluminum?
(a) 13
(b) 27
(c) 3+
(d) 14
9. Which of the following statements is true?
(a) An ion is negative if it has more protons than it has electrons.
(b) An ion is negative if it has more electrons than it has neutrons.
(c) An ion is neutral if it has an equal number of electrons and protons.
(d) An ion is positive if it has more electrons than it has protons.
10. Which of the following compounds is NOT correctly identified?
(a) Carbon disulfide is a molecular compound.
(b) Phosphorus pentachloride is a molecular compound.
(c) KF is a molecular compound.
(d) Sodium bromide is an ionic compound.
11. Which of the following formulas does NOT represent a covalent molecule?
(a) Cl2
(b) CH4
(c) O2
(d) CaF2
12. What number does the prefix hexa- represent?
(a) 2
(b) 4
(c) 6
(d) 8
Page 3 of 9
Part B: Short Answer – Thinking and Inquiry (4 marks each)
1. Describe the main difference between a qualitative physical property and a quantitative
physical property, and give one example of each.
2. Three liquid layers of differing densities in a graduated cylinder are shown below. Which
liquid has the greatest density? How do you know?
3. How many valence electrons does an atom of each of the following elements have? Which
one of the two is more reactive?
a) Ca
b) Ne
Page 4 of 9
4. How does the physical location of metalloids in the periodic table reflect the properties of
metalloids?
5. Which compound would you expect to have a lower melting point, nitrogen monoxide or
magnesium chloride? Briefly explain.
6. Why do most ionic compounds have higher melting points compared to molecular
compounds? Why do some polar molecular compounds have higher melting points compared
to other non-polar molecular compounds.
Page 5 of 9
Part C: Problem Solving Questions – Communication and Application
1. Dry ice, which is solid carbon dioxide, is often used to create fog effects during a concert.
The fog you see however, is not carbon dioxide, it is droplets of liquid water formed as a
result of the solid carbon dioxide change state, absorbing energy and lowering the ambient
temperature. Describe and explain the two changes of state that occur during this effect. (C4,
A4)
2. The following graph shows how long it takes two different liquids: water and corn syrup, to
flow through a 100cm length of tubing. Use this graph to determine which fluid is more
viscous and the identity of both liquids. Explain your answer. (C4, A4)
Page 6 of 9
3. a) On the periodic table of elements, what is the name of group 1, 2, 17, and 18 respectively?
b) Between group 1 and 2, which is more reactive, explain.
c) Identify the main difference between group 17 and 18, and how this leads to difference in
their chemical property.
(C6, A6)
4. A new scam on the internet involves people selling samples of sodium that they collected
from a secret river in the mountains, which has majestic healing power over common sodium
found elsewhere. Write a short statement to explain why this is a scam. (C2, A2)
Page 7 of 9
5. Examine the Bohr-Rutherford model of carbon tetrafluoride on the right. How many
electrons are used in covalent bonds in the molecule? How many electrons in the outer
energy levels of the atoms are not in bonds? (C2, A2)
6. Some molecular compounds, such as those used in edible films, are soluble in water.
Surgeons often use a soluble material for stitches inside the body. What is a major benefit of
this technology? (C2, A2)
Page 8 of 9
7. Draw a Bohr-Rutherford model for a molecule of florine gas (F2). (C4, A4)
Page 9 of 9
