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WESTERFORD
HIGH SCHOOL
CLAREMONT
HIGH SCHOOL
Physical Science
GRADE 10
MAY 2013
EXAMINER: G SHAW
TIME:
MARKS:
2 HOURS
100 MARKS
INSTRUCTIONS
1.
Answer ALL the questions.
2.
Answer SECTION A (Questions 1 and 2) on the ANSWER SHEET provided.
3.
Answer SECTION B on the folio provided. Start each new question at the top of the
page. There are FOUR long questions in Section B (Question 3 to 6).
4.
Do not staple your answer sheet! Simply place the pages in the correct order, with the
answer sheet on top, and hand in like that. They must not be stapled together.
5.
Number the answer in the same way that the questions are numbered. Leave one line
open between subsections of questions. For example, between 5.1 and 5.2.
6.
Non-programmable calculators may be used. Appropriate mathematical instruments may
be used.
7.
Consult the data sheet provided.
8.
Use black or blue ink only for your answers, other than sketches and diagrams where a
sharp pencil must be used.
9.
Give ALL the formulae used and show your working, including substitutions. Your
answer must be calculated correctly to two decimal places.
10.
A penalty of 1% will be imposed for each instruction disregarded.
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QUESTION 1
Give ONE word/term for each of the following descriptions. Write only the word/term next to
the question number on your answer page.
1.1
The type of wave where the motion of the particles of the medium is parallel to the
motion of the wave.
(1)
1.2
Half the perpendicular distance between the crest and trough of the wave.
(1)
1.3
Atoms differing by number of neutrons only.
(1)
1.4
Elements that readily donate electrons in bonding.
(1)
1.5
A substance made up by a giant covalent network with the ability to conduct electricity.(1)
/5/
QUESTION 2
Four possible options are provided as answers to the following questions. Each question has only
ONE correct answer. Choose the answer and mark only the letter corresponding to your answer
( A – D ) next to the question number on your answer page.
2.1
CuSO4 is the chemical formula for:
A
Copper (I) sulfate
B
Copper (II) sulfide
C
Copper (II) sulfate
D
Copper (I) sulfite
2.2
Which one of the following formulae for compounds of an alkaline earth metal M is not correct?
A
MOH
B
M(NO3)2
C
M3(PO4)2
D
MO
(2)
(2)
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2.3
Which statement(s) below is/are true regarding the following two ions?
32
16
A 2 ;
40
20
B 2
i) Each atom has twice as many neutrons as protons.
ii) They both have the same number of electrons.
iii) Elements A and B are both in the same group on the periodic table.
A
(i) and (ii)
B
(ii) and (iii)
C
Only (i)
D
Only (ii)
2.4
Magnesium nitrate is an example of:
A
a covalent network structure.
B
a covalent molecular structure.
C
an ionic compound.
D
a metallic compound.
2.5
One difference between red light and infrared light is that red light rays have:
A
a longer wavelength.
B
less particle nature.
C
a higher frequency.
D
greater velocity.
(2)
(2)
(2)
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2.6
Which of the following would be a correct example of constructive interference in
waves:
+
…a second later…
=
A
B
C
D
(2)
2.7
Which of the following represents chemical change the best?
A
Hydrogen peroxide decomposing in the presence on manganese dioxide
B
Dry ice subliming to yield carbon dioxide
C
Low energy input
D
Distillation
(2)
2.8
A reaction in which very strong bonds in the reactants are broken before new, weaker
bonds are formed in the products.
A
Exothermic
B
Endothermic
C
Spontaneous
D
Ionic bonding
(2)
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QUESTION 3 ( Start this question on a new page. )
3.1
Consider the diagram
alongside, which depicts the
relative sizes of three
elements, before answering
the questions that follow:
3.1.1 Lithium, sodium and
potassium are all elements
of group 1. What is the
collective name for
group 1 elements?
(1)
3.1.2 Potassium’s electron
configuration has been
described as [Ar] 4s1. Give
the full sp-notation for
potassium.
(2)
The inner electrons shield the valence electron so
that each valence electron in effect only “feels” a +1
charge from the nucleus.
3.1.3 The caption at the bottom of the diagram talks about a “valence electron”. What are
“valence electrons”?
(2)
3.1.4 Describe, and then explain the general trend of reactivity for group 1 elements. Use the
information in the diagram to substantiate your explanation.
(4)
[9]
3.2
Nitrogen is the most common element in the atmosphere, constituting 78% of the Earth’s
atmosphere. Nitrogen occurs naturally as a diatomic molecule, it is a colourless and
odourless gas with a boiling point of -196oC.
3.2.1 Draw an Aufbau diagram for nitrogen.
(3)
3.2.2 Consider the very low boiling point of nitrogen. What does this tell us about the bonds
between nitrogen molecules in liquid nitrogen.
(2)
3.2.3 Use Lewis structures to depict the bonding process when nitrogen reacts with hydrogen. (3)
3.2.4 Give the common name for the compound that forms as a result of the reaction in 3.2.3. (1)
[9]
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QUESTION 4 ( Start this question on a new page. )
4.1
A very important reaction in the refining of iron takes place when iron(III)oxide is
reacted with carbon monoxide, in a blast furnace, to produce iron and carbon dioxide.
The chemical equation for this reaction is given below.
Fe2O3
+
CO
Fe
+
CO2
4.1.1
Balance the above chemical equation.
(3)
4.1.2
What type of chemical bonding is found in iron(III)oxide?
(1)
4.1.3
What type of chemical bonding is found in carbon monoxide?
(1)
4.1.4
Tabulate the main differences between ionic and covalent bonding. Discuss the types of
elements involved in the types of bonding, as well as the role of electrons in the
different bonds.
(4)
[9]
Consider again the chemical equation in 4.1, above. Iron is amongst the reactants, as
well as the products.
4.2
4.2.1
Is this reaction an example of physical change? Explain your answer.
(3)
4.2.2
Discuss physical and chemical change in terms of bonding.
(4)
[7]
4.3
Iron has three main isotopes:
54
Fe (± 5,85%)
Fe (± 91,76%)
57
Fe (± 2,39%)
56
4.3.1
Define the term ‘isotope’.
4.3.2
Use the information above to determine the approximate relative atomic mass for iron. (3)
[5]
(2)
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QUESTION 5
5.1
( Start this question on a new page. )
The following table shows the first ionisation energies for the elements of periods 1
and 2.
5.1.1 What is the meaning of the term first ionization energy?
(2)
5.1.2 State the pattern of first ionization energies in a period.
(1)
5.1.3 Does electronegativity follow the same trend? Write YES or NO.
(1)
5.1.4 Which TWO elements exert the strongest attractive forces on their electrons?
Justify your answer with a reason in one line only. (Use the data from the table to
answer your question.)
(2)
5.1.5 It is safer to use helium gas than hydrogen gas in balloons. Which property of
helium makes it a safer substitute?
(2)
[8]
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5.2
Below is a diagram showing the displacement of the particles of a transverse wave versus
time.
5.2.1 Determine the period of this wave.
(2)
5.2.2 Determine the frequency of the wave by inspection. Do not do a calculation.
(2)
5.2.3 Give the amplitude of the wave in SI units.
(2)
5.2.4 Answer the following questions on the replicated diagram on your answer sheet.
a) Label a point (B) that is in phase with point P.
(1)
b) Show the new position (point P’) that point P will occupy exactly 1 s later.
(2)
c) Mark two positions in one wavelength apart where the velocity of the particles of the
medium is zero. Label these positions as D1 and D2.
(2)
[11]
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QUESTION 6
6.1
( Start this question on a new page. )
Sunbirds and hummingbirds are known
for their ability to hover alongside a
flower while they suck nectar out as
food.
The Ruby-throated hummingbird,
which occurs in North America, hovers
by beating its wings at a rate of about
70 beats per second. The sound that
this flapping makes gives the bird its
name.
6.1.1
6.1.2
What is the frequency of this sound?
Determine the wavelength of this sound, if it travels at a speed of 340m.s-1.
(1)
(3)
[4]
6.2
The term echolocation refers to an ability that certain mammals possess that enables
them essentially to "see" with their ears by listening for echoes. Dolphins, for example,
echolocate by producing trains of clicking sounds and then receiving and interpreting
the resulting echo.
Clicking at this frequency, a dolphin determines that a fish it can eat is 180 m away.
The echo from its click takes 0,24 seconds to reach the dolphin from the moment it first
clicked.
6.2.1
A dolphin click has a period of approximately 120 microseconds (120 x 10-6 s). What is
the frequency of these clicks?
(3)
6.2.2
Use the information above to determine the speed of sound in water.
6.3
Peter gets confused by the concept of radio waves. He does not understand that a radio
wave is part of the electromagnetic spectrum, while a sound wave is a simple
longitudinal wave.
6.3.1
Explain any two fundamental differences between sound waves and waves of the
electromagnetic spectrum.
(4)
[7]
(4)
6.3.2
Calculate the energy of a photon of a radio wave that has a frequency of 175 x 106 Hz.(3)
6.3.3
A photon of light has 4,11 x 10-19J. Determine the wavelength of the incident light. (3)
[10]
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TOTAL 100
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