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Mayank1444
@mayank1444
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Joined: Oct 11, 2021
Last seen: Nov 14, 2021
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Answer to: State two reasons for supposing that brass is a mixture and not a compound.

Brass is a mixture because 1. It does not have a fixed composition. 2. It shows the properties of its constituents.

4 years ago
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Answer to: Define a mixture. Give two points of evidence to show that sugar solution is a mixture.

Mixture consists of two or more different kinds of particles or substances but not chemically bounded. Sugar solution is a mixture because 1. It...

4 years ago
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Answer to: Define a compound. Give two points of evidence to show that sodium chloride is a compound.

A chemical compound is a substance made up of two or more elements combined together chemically in a fixed proportion by mass. Sodium chloride is a...

4 years ago
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Answer to: Give two reasons for supposing that water is a compound and not a mixture.

Water is a compound because 1. Its composition is fixed and it is inseparable. 2. The property of water is different from its constituents.

4 years ago
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Answer to: Is air a mixture or a compound? Give three reasons for your answer.

Air is a mixture because 1. Its constituents can be separated example: oxygen, nitrogen etc. by physical process. 2. It does not have a fixed boi...

4 years ago
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Answer to: How would you confirm that a colourless liquid given to you is pure water?

We boil the colourless liquid and if it starts boiling at 100℃ then it might be water. We can check it by checking reactivity with some metals that re...

4 years ago
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Answer to: Give reason why: (a) Copper metal is used for making electric wires. (b) Graphite is used for making electrode in a dry cell.

(a) Copper can be used for making electric wires because they are ductile in nature as copper is a metal. (b) Graphite is a non-metal which has the...

4 years ago
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Answer to: State any two properties for believing that aluminium is a metal.

Metals are malleable, ductile and sonorous. Therefore aluminium can be considered as a metal because it possesses these properties.

4 years ago
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Answer to: Compare the properties of metals and non-metals with respect to (i) malleability (ii) ductility, and (iii) electrical conductivity.

(i) Malleability - Metals show this property but non-metals don’t. (ii) Ductility - Metals show this property but non-metals don’t. (iii) Electr...

4 years ago
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Answer to: State two physical properties on the basis of which metals can be distinguished from non-metals.

Metals are malleable and ductile that is they can be drawn to thin wires and can be hammered but non-metals are neither malleable nor ductile.

4 years ago
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Answer to: What are the three groups into which all the elements can be divided? Name two elements belonging to each group.

Elements can be divided into metals, non-metals and metalloids. Metals: Aluminium and copper Non-metals: Potassium and calcium Metalloids: Ar...

4 years ago
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Answer to: Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.

Hydrogen and oxygen are considered as elements which cannot split into different substances by applying any kind of energy like heat or electricity wh...

4 years ago
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Answer to: Name two solid, liquid and two gaseous elements at room temperature.

Two solid elements at room temp. - Iron and copper Two liquid elements at room temp. - Mercury and bromine Two gaseous elements at room temp. - ...

4 years ago
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Answer to: State three reasons why you think air is a mixture and water is a compound.

Air is a mixture because 1. It contains two or more pure substances. 2. By physical processes it can be separated into simpler substance. 3. It...

4 years ago
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Answer to: What is the other name for impure substances? Give two examples of impure substances.

Other name for impure substance is Mixture. Examples: Milk and sea water.

4 years ago
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Answer to: What are the two types of pure substances? Give one example of each type.

(i) Pure substances which are made up of same kind of atoms. Example: Sulphur (ii) Pure substances which are made up of same kind of molecules. ...

4 years ago
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Answer to: What are pure substances? Give two examples of pure substances.

A pure substance is made up of same type of particles or atoms. All the elements and compounds are pure substances because they contain the same kind ...

4 years ago
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