Class 8 Chapter - Metals and Non-Metals CBSE and NCERT Study help
Class 8 Notes : Metal and non metals Read/Download
Class 8 MCQ On Metal and Non metal-1 Read/Download Class 8 MCQ on metal and Non metal-2 Read/Download Class 8 Chemical Properties of Metals Read/Download Fill in the blanks :Metal and Non metal Read/Download Class 8 assignments Metals and Non-Metals Download File Class8 Basic sciences Metal and non Metal Read/ Download |
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Learnwell science chapter Metals and Non metal Questions With answer class 8 |
Basic science chapter Metals and Non metal Questions answer class 8 |
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Q. Name the scientist who classified Elements into metals and non metals?
Ans: Arrhenius
Q. Name a liquid metal.
Ans: Mercury
Q. Name a liquid non metal.
Ans: Bromine
Q. Name two soft metal that can be cut with knife?
Ans: Lithium, Potassium and Sodium are soft metal
Q. Name two metals having low melting points that melt in the palm of the hand?
Ans: Gallium and Ceasium
Q. Name metal having highest melting points .
Ans Tungesten
Q. Why metals are called malleable?
Ans: Metals can be beaten into thin sheets so they are called malleable. This properties if metal is called malleability.
Q. Name the hardest natural substance
Ans: Diamond
Q. Name a Non metals that are good conductors of electricity .
Ans: Graphite
Q. Some metal oxides show acidic and basic properties. What are they called ?
Ans: Amphoteric oxides Eg :- Aluminum oxide, Zinc oxide etc.
Q.What is aqua regia?
Ans: Aqua regia is a mixture of concentrated nitric acid and concentrated hydrochloric acid in the ratio 1:3.
Q. Name a metal that is poorest conductor of heat?
Ans: Lead
Q. Name a non metal which When red hot reacts with steam. What happen as a result of the reaction
Ans: Carbon is a nonmetal. When it is red hot, it reacts with steam. This reaction forms a gaseous mixture of carbon monoxide and hydrogen, called water gas. The following reaction occurs:
C (red hot) + O2 --------------> (water gas)
Q. Mention five physical properties of metals.
Ans : Five physical characteristics of metals are:
(a) They have a high tensile strength; therefore, they cannot be broken down easily.
(b) They are malleable; i.e., they can be beaten into thin sheets.
(c) They are ductile; i.e., they can be stretched into thin wires.
(d) They are good conductors of heat.
(e) They are good conductors of electricity.
Q.How would you use the activity series while studying the displacement of hydrogen from acids by metal?
Ans: Activity series is an ordered arrangement of metals and hydrogen (nonmetal) with respect to their activities.
The reactivity of a metal decreases top to bottom in the activity series.
For example : Metals that are placed above hydrogen in the activity series can displace hydrogen from dilute hydrochloric acid and sulphuric acid.
Metals that are placed below hydrogen in the activity series cannot displace hydrogen from acids.
2 NA + 2HCl ------------------> 2NaCl + H2
Cu + HCl ------------------> No reaction
Q. Describe an activity to show that the lead of pencil is good conductors of electricity but sulpher does not.
Ans: Following activity shows that the lead of a pencil conducts electricity and sulphur does not.
Take a pencil and sharpen both its ends. Connect the ends of the pencil to an electric circuit, formed by connecting a bulb to the cell. The bulb glows when pencil is connected to it. This shows that the lead of a pencil conducts electricity. This occurs because lead contains graphite, which is a good conductor of electricity.
Now, replace the pencil with a piece of sulphur. The bulb will stop glowing. This shows that sulphur does not conduct electricity.
Q. Name two metals react vigorously with cold water. Name one metal which,if ignited continue to burn in steam?
Ans: Potassium and sodium are two metals that react vigorously with cold water.
Magnesium is a metal that continues to burn in steam, if it is ignited.
Q. Why is graphite not used for making electric cable?
Ans: Graphite is a non metal that is brittle and cannot draw into wire. This is why graphite is not used for making
electric cable
Q. Could you store 500 ml Zinc sulphate solution in an aluminum vessel overnight? Give reason for your answer.
Ans: Aluminium is more reactive than zinc therefore displace zinc from Zinc sulphate solution and form salt with
evolution of hydrogen gas. This is why we do not store Zinc sulphate solution in an aluminum vessel overnight
Ans: Arrhenius
Q. Name a liquid metal.
Ans: Mercury
Q. Name a liquid non metal.
Ans: Bromine
Q. Name two soft metal that can be cut with knife?
Ans: Lithium, Potassium and Sodium are soft metal
Q. Name two metals having low melting points that melt in the palm of the hand?
Ans: Gallium and Ceasium
Q. Name metal having highest melting points .
Ans Tungesten
Q. Why metals are called malleable?
Ans: Metals can be beaten into thin sheets so they are called malleable. This properties if metal is called malleability.
Q. Name the hardest natural substance
Ans: Diamond
Q. Name a Non metals that are good conductors of electricity .
Ans: Graphite
Q. Some metal oxides show acidic and basic properties. What are they called ?
Ans: Amphoteric oxides Eg :- Aluminum oxide, Zinc oxide etc.
Q.What is aqua regia?
Ans: Aqua regia is a mixture of concentrated nitric acid and concentrated hydrochloric acid in the ratio 1:3.
Q. Name a metal that is poorest conductor of heat?
Ans: Lead
Q. Name a non metal which When red hot reacts with steam. What happen as a result of the reaction
Ans: Carbon is a nonmetal. When it is red hot, it reacts with steam. This reaction forms a gaseous mixture of carbon monoxide and hydrogen, called water gas. The following reaction occurs:
C (red hot) + O2 --------------> (water gas)
Q. Mention five physical properties of metals.
Ans : Five physical characteristics of metals are:
(a) They have a high tensile strength; therefore, they cannot be broken down easily.
(b) They are malleable; i.e., they can be beaten into thin sheets.
(c) They are ductile; i.e., they can be stretched into thin wires.
(d) They are good conductors of heat.
(e) They are good conductors of electricity.
Q.How would you use the activity series while studying the displacement of hydrogen from acids by metal?
Ans: Activity series is an ordered arrangement of metals and hydrogen (nonmetal) with respect to their activities.
The reactivity of a metal decreases top to bottom in the activity series.
For example : Metals that are placed above hydrogen in the activity series can displace hydrogen from dilute hydrochloric acid and sulphuric acid.
Metals that are placed below hydrogen in the activity series cannot displace hydrogen from acids.
2 NA + 2HCl ------------------> 2NaCl + H2
Cu + HCl ------------------> No reaction
Q. Describe an activity to show that the lead of pencil is good conductors of electricity but sulpher does not.
Ans: Following activity shows that the lead of a pencil conducts electricity and sulphur does not.
Take a pencil and sharpen both its ends. Connect the ends of the pencil to an electric circuit, formed by connecting a bulb to the cell. The bulb glows when pencil is connected to it. This shows that the lead of a pencil conducts electricity. This occurs because lead contains graphite, which is a good conductor of electricity.
Now, replace the pencil with a piece of sulphur. The bulb will stop glowing. This shows that sulphur does not conduct electricity.
Q. Name two metals react vigorously with cold water. Name one metal which,if ignited continue to burn in steam?
Ans: Potassium and sodium are two metals that react vigorously with cold water.
Magnesium is a metal that continues to burn in steam, if it is ignited.
Q. Why is graphite not used for making electric cable?
Ans: Graphite is a non metal that is brittle and cannot draw into wire. This is why graphite is not used for making
electric cable
Q. Could you store 500 ml Zinc sulphate solution in an aluminum vessel overnight? Give reason for your answer.
Ans: Aluminium is more reactive than zinc therefore displace zinc from Zinc sulphate solution and form salt with
evolution of hydrogen gas. This is why we do not store Zinc sulphate solution in an aluminum vessel overnight
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