i) Atom.
Is the smallest particle of an element which can take part in chemical change.
ii) Compound.
A pure substance made up of two or more elements chemically combined.
iii) Element.
A pure substance which cannot be split into simpler substance by chemical means
marto answered the question on October 1, 2019 at 09:14
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Write the names of the elements represented by symbols.
i) K –
ii) Cl –
iii) Fe –
iv) Mg –
v) C –
vi) Be-
Date posted: October 1, 2019. Answers (1)
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Date posted: October 1, 2019. Answers (1)
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The graph below shows the shape of the curve obtained by a student when solid X was heated to boiling.
a) Determine the melting point of solid X.
b) After the experiment the student concluded that substance x was pure substance. Explain why he concluded so.
c) If candle wax was used in the above experiment the portion QR would be horizontal. What does this tell us about candle wax?
Date posted: October 1, 2019. Answers (1)
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i) Magnesium oxide.
ii) Zinc chloride
iii) Sodium sulphate.
iv) Aluminium nitrate(Solved)
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i) Magnesium oxide.
ii) Zinc chloride
iii) Sodium sulphate.
iv) Aluminium nitrate
Date posted: October 1, 2019. Answers (1)
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a) Name the process labeled a, b, c and d.
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Date posted: October 1, 2019. Answers (1)
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Date posted: October 1, 2019. Answers (1)
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Date posted: October 1, 2019. Answers (1)
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(i) Atom
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(i) Atom
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Date posted: October 1, 2019. Answers (1)
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(a) Name the two oxides
(b) State the nature of the solution when the above mentioned oxides are...(Solved)
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Date posted: October 1, 2019. Answers (1)
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(i) Explain the term pollutant
(ii) State how soot is formed from hydrocarbons(Solved)
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(i) Explain the term pollutant
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Date posted: October 1, 2019. Answers (1)
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Date posted: October 1, 2019. Answers (1)
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Date posted: October 1, 2019. Answers (1)
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a) Explain why air is considered as a mixture
b) Identify the substance that is removed at the filtration stage
c) Explain why Carbon (IV) oxide and water are removed before liquefaction of air
d) Identify the component that is collected at -186°C
Date posted: October 1, 2019. Answers (1)
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(a)...(Solved)
In temperate countries, salt is sprayed on roads to defrost and clear roads but the long term effect on this practice is costly to motorist.
(a) Explain the role of salt in defrosting the ice.
(b) Explain why the long term effect is costing to motorist.
Date posted: October 1, 2019. Answers (1)
- Study the table below.(Solved)
Study the table below.
(a) Which elements belong to the same period of the periodic table?
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(c) Compare the atomic and ionic radii of element L.
Date posted: October 1, 2019. Answers (1)
- A student set-up the apparatus below in order to determine the percentage by volume of oxygen in air.(Solved)
A student set-up the apparatus below in order to determine the percentage by volume of oxygen in air.
a) Why did water rise when the reaction had stopped?
b) The student wrote the expression for the percentage by volume of oxygen in air as
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c) What should have been done after the reaction had stopped in order to get a correct volume.
Date posted: October 1, 2019. Answers (1)
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Blue litmus remained blue in both solutions. Methyl orange remained...(Solved)
Two solutions J and K were tested with blue litmus papers and methyl orange indicator.
Blue litmus remained blue in both solutions. Methyl orange remained orange in K but turned yellow in J.
(a) What is the nature of substance J? Explain.
(b) Give an example of a substance that K is likely to be.
Date posted: October 1, 2019. Answers (1)
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Date posted: October 1, 2019. Answers (1)
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Date posted: October 1, 2019. Answers (1)
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Date posted: October 1, 2019. Answers (1)