Modern atomic theory is, of course, a little more involved than Dalton's theory but the essence of Dalton's theory remains valid. Today we know that atoms can be destroyed via nuclear reactions but not by chemical reactions. Also, there are different kinds of atoms (differing by their masses) within an element that are known as "isotopes", but isotopes of an element have the same chemical properties.
MWALIMUWA answered the question on October 9, 2017 at 11:45
- Explain why a substance conducts electric current when in molten state and not in solid state.(Solved)
Explain why a substance conducts electric current when in molten state and not in solid state.
Date posted: September 28, 2017. Answers (1)
- A dry cell is used as a source of electric current.
State the role of manganese (IV) oxide mixed with carbon(Solved)
A dry cell is used as a source of electric current.
State the role of manganese (IV) oxide mixed with carbon
Date posted: September 28, 2017. Answers (1)
- During the extraction of zinc metal, the ore is crushed into powder and mixed with water and oil.
Air is also blown through the mixture.
i) What...(Solved)
During the extraction of zinc metal, the ore is crushed into powder and mixed with water and oil.
Air is also blown through the mixture.
i) What name is given to the process described above?
ii) The hull of a ship is made using Iron and blocks of zinc to prevent rusting. How does zinc
prevent the rusting of iron?
iii) Explain the process named in (i) above occurs.
Date posted: September 28, 2017. Answers (1)
- Fossil fuels are commonly used as sources of energy. Hydrogen gas is also a source of energy.
State and explain why hydrogen is a more attractive...(Solved)
Fossil fuels are commonly used as sources of energy. Hydrogen gas is also a source of energy.
State and explain why hydrogen is a more attractive fuel than the fossil fuels.
Date posted: September 28, 2017. Answers (1)
- Giving a reason, state what would be observed if concentrated hydrochloric acid is added
drop wise to a solution of Bismuth chloride.(Solved)
Giving a reason, state what would be observed if concentrated hydrochloric acid is added
drop wise to a solution of Bismuth chloride.
Date posted: September 28, 2017. Answers (1)
- Name the following processes (i) When anhydrous calcium chloride was left in an open beaker overnight a solution was formed (ii) When sodium carbonate decahydrate crystals are...(Solved)
Name the following processes
i) When anhydrous calcium chloride was left in an open beaker
overnight a solution was formed.
ii) When sodium carbonate decahydrate crystals are left in an open beaker for some days it turned
into powder.
Date posted: September 28, 2017. Answers (1)
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Briefly explain how the calcium is separated from sodium in the down’s cell.
Date posted: September 28, 2017. Answers (1)
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List the main uses of Sulphur
Date posted: September 27, 2017. Answers (1)
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List and explain the physical properties of Sulphur
Date posted: September 27, 2017. Answers (1)
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Name the two allotropes of sulphur
Date posted: September 26, 2017. Answers (1)
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State three uses of hydrogen nitrate
Date posted: September 26, 2017. Answers (1)
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Define the term catenation?
Date posted: September 26, 2017. Answers (1)
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Both graphite and molten sodium chloride conduct electricity,state how each of the substances conduct electricity?
Date posted: September 26, 2017. Answers (1)
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List five substances that undergo sublimation?
Date posted: September 26, 2017. Answers (1)
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Date posted: September 26, 2017. Answers (1)
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Define the term chromatography?
Date posted: September 26, 2017. Answers (1)
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Name three methods used in separation of mixtures?
Date posted: September 26, 2017. Answers (1)
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What is a conductor?
Date posted: September 26, 2017. Answers (1)
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Define the term flame?
Date posted: September 26, 2017. Answers (1)
- An experiment was carried out to investigate the rate of reaction shown below
Sucrose ?Fructose + Glucose ...(Solved)
An experiment was carried out to investigate the rate of reaction shown below
Sucrose →Fructose + Glucose
For the products fructose and glucose to be formed, it was found that substance K was to be added and the temperature maintained at 370C. When another substance L was added, the reaction slowed down and eventually stopped
a) Suggest the identify of substances K and L
b) Other than temperature state three ways by which the rate of reaction could be increased
c) Explain how substance L slowed down the reaction
Date posted: September 25, 2017. Answers (1)