Magnesium has a giant metallic structure in which the positive nucleus are immersed in a sea / cloud of electrons While silicon has a giant atomic stmcture in which the atoms are joined by strong covalent bonds hence silicon is harder than Magnesium metal hence the high melting point.
lemass answered the question on January 21, 2019 at 08:19
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How many atoms of each element are present in each of the following compounds? Lithium chloride
(Solved)
How many atoms of each element are present in each of the following compounds? Lithium chloride
Date posted:
January 7, 2019
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Answers (1)
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All sulphates are soluble except two. Name them?
(Solved)
All sulphates are soluble except two. Name them?
Date posted:
January 5, 2019
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Answers (1)
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Explain why bromine is a liquid at room temperature while chlorine is a gas
(Solved)
Explain why bromine is a liquid at room temperature while chlorine is a gas
Date posted:
January 3, 2019
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Answers (1)
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Starting with zinc oxide, describe how you can prepare a sample of lead ii sulphate
(Solved)
Starting with zinc oxide, describe how you can prepare a sample of lead ii sulphate
Date posted:
January 2, 2019
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Answers (1)
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In an experiment a piece of magnesium ribbon was cleaned with steel wool 2.4g of the clean ribbon was placed in a crucible and completely...
(Solved)
In an experiment a piece of magnesium ribbon was cleaned with steel wool 2.4g of the clean ribbon was placed in a crucible and completely burnt in oxygen.after cooling the product weighted 4.0g.
(a)explain why it was necessary to clean the magnesium ribbon?
(b)what observation was made in the crucible after burning?
(c)why was there an increase in mass?
(d)write the equation for reaction which took place in the crucible?
(e)the product in the crucible was shaken with water and filtered. Explain the observation which was made when blue and red litmus papers were dropped into the filtrate.
Date posted:
December 30, 2018
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Answers (1)
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A student crushed the seeds and then added propane instead of water to extract oil from castor oil seeds. Why did he use propane instead...
(Solved)
A student crushed the seeds and then added propane instead of water to extract oil from castor oil seeds. Why did he use propane instead of water and why were the seeds first crushed?
Date posted:
December 26, 2018
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Answers (1)
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Explain what is observed when ammonia gas is bubbled into copper sulphate solution till in excess
(Solved)
Explain what is observed when ammonia gas is bubbled into copper sulphate solution till in excess
Date posted:
December 20, 2018
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Answers (1)
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Outline the physical properties of oxygen gas
(Solved)
Outline the physical properties of oxygen gas.
Date posted:
December 20, 2018
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Answers (1)
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A hydrocarbon consist of 92.3% carbon. Its molecular mass is 26. Calculate its molecular formula.
(Solved)
A hydrocarbon consist of 92.3% carbon. Its molecular mass is 26. Calculate its molecular formula.
Date posted:
December 16, 2018
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Answers (1)
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What happens when ammonium chloride is heated?
(Solved)
What happens when ammonium chloride is heated?
Date posted:
December 12, 2018
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Answers (1)
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Crystals of sodium carbonate decahydrate were exposed to air for about four days
1. State what was observed
2. Name the process that took place
3....
(Solved)
Crystals of sodium carbonate decahydrate were exposed to air for about four days
1. State what was observed
2. Name the process that took place
3. Write an equation for the reaction that occurred
Date posted:
December 11, 2018
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Answers (1)
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State the uses of ammonia
(Solved)
State the uses of ammonia.
Date posted:
December 7, 2018
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Answers (1)
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Name the type of bond and structure formed between the reaction of boron and fluorine
(Solved)
Name the type of bond and structure formed between the reaction of boron and fluorine.
Date posted:
December 6, 2018
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Answers (1)
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When a few drops of potassium permanganate are added to an aqueous solution of ferrous sulphate, solution turns brown. On the other hand, when the...
(Solved)
When a few drops of potassium permanganate are added to an aqueous solution of ferrous sulphate, solution turns brown. On the other hand, when the test is repeated using sodium molybdate instead of potassium permanganate no similar colour change is observed.
Date posted:
November 29, 2018
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Answers (1)
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What state is foam in?
(Solved)
What state is foam in?
Date posted:
November 28, 2018
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Answers (1)
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Define the term soil acidity as studied in soil chemistry.
(Solved)
Define the term soil acidity as studied in soil chemistry.
Date posted:
November 27, 2018
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Answers (1)
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What are the ingredients used to make soap?
(Solved)
What are the ingredients used to make soap?
Date posted:
November 21, 2018
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Answers (1)
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What is the process by which Aluminium reduces Iron(III)oxide?
(Solved)
What is the process by which Aluminium reduces Iron(III)oxide?
Date posted:
November 19, 2018
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Answers (1)
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What is the chemical equation of Copper II oxide burned in presence of dry carbon monoxide.
(Solved)
What is the chemical equation of Copper II oxide burned in presence of dry carbon monoxide.
Date posted:
November 17, 2018
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Answers (1)
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Why is not advisable to grow vegetables especially sukuma week on roadside?
(Solved)
Why is not advisable to grow vegetables especially sukuma week on roadside?
Date posted:
November 16, 2018
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Answers (1)