a)i) Electrons are negatively charged while protons are positively charged
ii) Electrons have neglible mass while protons have significant mass (1 a.m.u)
b) i) F
ii) 13 + 14 = 27
iii) E2G3
iv) Ionic bond.
v) E has a small atomic radius than C. This is because E has greater nuclear charge hence its electrons
are pulled strongly.
johnmulu answered the question on April 10, 2017 at 09:55
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The diagram below shows the bonding between aluminium chloride and ammonia.
(Solved)
The diagram below shows the bonding between aluminium chloride and ammonia.
a) Name the types of bonds that exists in the molecule
b) How many electrons are used for bonding in the molecule?
Date posted:
April 10, 2017
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Answers (1)
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The table below gives atomic numbers of elements represented by the letters A, B, C and D.
(Solved)
The table below gives atomic numbers of elements represented by the letters A, B, C and D.
Use the information to answer the questions that follow.
a) Name the type of bonding that exists in the compound formed when A and D react.
b) Select the letter which represents the best oxidizing agent. Give a reason for your answer.
Date posted:
April 10, 2017
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Answers (1)
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The diagram below is a section of a model of the structure of element T.
(Solved)
The diagram below is a section of a model of the structure of element T.
a) State the type of bonding that exists in T.
b) In which group of the periodic table does element T belong? Give a reason.
Date posted:
April 10, 2017
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Answers (1)
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Study the information given in the table below and answer the questions that follow.
The letters do not represent the actual symbols of the elements
(Solved)
Study the information given in the table below and answer the questions that follow.
The letters do not represent the actual symbols of the elements
a) Select the elements which belong to the same:
i) Group
ii) Period
b) Which element
i) is in gaseous state at room temperature? Explain. (Take room temperature to be 298K)
ii) Does not form an oxide?
c) Write the
i) Formula of the nitrate of element T.
ii) Equation for the reaction between elements S and U
d) What type of bond would exists in the compound formed when U and T react? Give a reason for your answer
e) The aqueous sulphate of element W was electrolyzed using inert electrodes. Name products formed at the:
i) Cathode
ii) Anode
Date posted:
April 10, 2017
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Answers (1)
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The table below shows properties of some elements A, B, C and D which belong to the same periodic table. The letters are not the actual symbols of the elements.
(Solved)
The table below shows properties of some elements A, B, C and D which belong to the same periodic table. The letters are not the actual symbols of the elements.
a) Arrange the elements in order they would appear in the periodic. Give a reason
b) Select the metallic element which is the better conductor of electricity. Give a reason.
Date posted:
April 10, 2017
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Answers (1)
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Four metal F, G, H and J were each separately added to cold water, hot water and steam. The table below is a summary of the observations made and the formulae of the hydroxides formed.
(Solved)
Four metal F, G, H and J were each separately added to cold water, hot water and steam. The table below is a summary of the observations made and the formulae of the hydroxides formed.
a) Which two elements are likely to be in the same group of the periodic table?
b) Arrange the metals in the order of their reactivity starting with the most reactive.
Date posted:
April 10, 2017
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Answers (1)
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The grid given below represents part of the periodic table. Study it and answer the questions that follow. (The letters do not represent the actual symbol of the elements)
(Solved)
The grid given below represents part of the periodic table. Study it and answer the questions that follow. (The letters do not represent the actual symbol of the elements)
i) What name is given to the group of elements to which C and F belong?
ii) Which letter represents the element that is the least reactive?
iii) What type of bond is formed when B and E react? Explain
iv) Write the formula of the compound formed when element D and oxygen gas react
Date posted:
April 10, 2017
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Answers (1)
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The table below gives the atomic numbers of elements W, X, Y and Z. The letters do not represent the actual symbols of the elements.
(Solved)
The table below gives the atomic numbers of elements W, X, Y and Z. The letters do not represent the actual symbols of the elements.
a) Which one of the elements is least reactive? Explain.
b) (i) Which two elements would react most vigorously with each other?
(ii) Give the formula of the compound formed when the elements in b (i) react.
Date posted:
April 7, 2017
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Answers (1)
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The table below gives information on four elements represented by letters K, L, M and N. Study it and answer the questions that follow. The letters do not represent the actual symbols of the elements.
(Solved)
The table below gives information on four elements represented by letters K, L, M and N. Study it and answer the questions that follow. The letters do not represent the actual symbols of the elements.
a) Which two elements have two similar properties? Explain.
b) What is the most likely formula of oxide of L?
c) Which element is a non-metal? Explain
d) Which one of the elements is the strongest reducing agent? Explain.
e) Explain why ionic radius of N is less than that of M.
f) Explain why the ionic radius of L is bigger than its atomic radius.
Date posted:
April 7, 2017
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Answers (1)
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The table below gives the number of electrons, protons and neutrons in substances X, Y and Z. Study it and answer the questions that follow.
(Solved)
The table below gives the number of electrons, protons and neutrons in substances X, Y and Z. Study it and answer the questions that follow.
a) Which letter represents an ion?
b) Which of the substances are isotopes? Give reason.
Date posted:
April 7, 2017
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Answers (1)
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The table below shows the number of valence electrons of the element P, Q and R.
(Solved)
The table below shows the number of valence electrons of the element P, Q and R.
a) Explain why P and R would not be expected to form a compound.
b) Write an equation to show the effect of heat on the carbonate of R.
c) Write the formula for the most stable ion of Q
Date posted:
April 7, 2017
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Answers (1)
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The set up below was used to investigate the reaction between dry hydrogen gas and copper (II) oxide.
(Solved)
The set up below was used to investigate the reaction between dry hydrogen gas and copper (II) oxide.
a) Name substance A.
b) State the observation made in the combustion tube.
c) Explain the observation stated in (b) above.
Date posted:
April 7, 2017
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Answers (1)
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The set up below was used to investigate the reaction between dry hydrogen gas and copper (II) oxide.
(Solved)
The set up below was used to investigate the reaction between dry hydrogen gas and copper (II) oxide.
a) Name substance A.
b) State the observation made in the combustion tube.
c) Explain the observation stated in (b) above.
Date posted:
April 7, 2017
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Answers (1)
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The set-up below was used to investigate the products of burning biogas (methane). Study it and answer the questions that follow.
(Solved)
The set-up below was used to investigate the products of burning biogas (methane). Study it and answer the questions that follow.
a) What product will be formed in test-tube Y?
b) State and explain the observations which will be made in Z.
Date posted:
April 7, 2017
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Answers (1)
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A student used the set up shown in the diagram below in order to study the reactions of some metals with steam. The experiment was carried out for ten minutes.
(Solved)
A student used the set up shown in the diagram below in order to study the reactions of some metals with steam. The experiment was carried out for ten minutes.
a) What observation would be made if gas F is ignited?
b) When the experiment was repeated using iron powder instead of magnesium ribbon, very little gas F was obtained.
i) Give a reason for this observation.
ii) What change in the conditions of the experiment should the student have made in order to increase the volume of gas F produced?
Date posted:
April 7, 2017
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Answers (1)
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An experiment was set up as shown in the diagram below:
(Solved)
An experiment was set up as shown in the diagram below:
a) Identify substance D.
b) Describe how the other product of the burning candle could be prevented from getting into the environment
Date posted:
April 7, 2017
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Answers (1)
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In laboratory experiment hydrogen gas was passed over heated copper (II) oxide as shown in the diagram below.
(Solved)
In laboratory experiment hydrogen gas was passed over heated copper (II) oxide as shown in the diagram below.
Describe a chemical test that can be used to identify the product E.
Date posted:
April 7, 2017
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Answers (1)
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a) A candle wax is mainly a compound consisting of two elements. Name the two elements
b) The set-up below was used to investigate the burning of a candle. Study it and answer the questions that follow.
(Solved)
a) A candle wax is mainly a compound consisting of two elements. Name the two elements
b) The set-up below was used to investigate the burning of a candle. Study it and answer the questions that follow.
i) What would happen to the burning candle if the pump was turned off?
ii) State and explain the changes that are likely to occur in tube N by the end of the experiment.
iii) Name two gases that come out through tube M.
iv) What is the purpose of calcium chloride in tube L?
v) Name another substance that could be used in the place of calcium oxide in tube N.
Date posted:
April 7, 2017
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Answers (1)
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Study the set-up below and answer the questions that follow
(Solved)
Study the set-up below and answer the questions that follow
a) Write an equation for the reaction, which takes place in the combustion tube.
b) What property of gas Z allows it to be collected as shown in the diagram?
Date posted:
April 7, 2017
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Answers (1)
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A student set up the experiment below to collect gas K. The gas K. The glass wool was heated before heating the zinc powder.
(Solved)
A student set up the experiment below to collect gas K. The gas K. The glass wool was heated before heating the zinc powder.
a) Why was it necessary to heat the moist glass wool before heating zinc powder?
b) What would happen if the zinc powder was heated before heating the glass wool?
c) What property of gas K makes it possible for it to be collected as shown in the diagram?
Date posted:
April 7, 2017
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Answers (1)