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Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q 47 and 48 pls
Answer
1
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q.46. Name an alloy of
(i) Aluminium used in construction of air crafts.
(ii) Lead in joining metals for electric works.
(iii) Copper used in household vessels.
Answer
2
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q.41. Metals at the top of the activity series do not occur in the free state. Explain.
Answer
4
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q 37. Name the products obtained when (a) zinc sulphate is roasted (b) Lime stone is calcined.
Q 39. Iron nails are not rusted if kept in boiled distilled water for a long time. Explain.
Answer
2
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q.35. Give reasons for the following:
(i) Metals replace hydrogen from dilute acids whereas non-metals do not.
(ii) Carbonate and sulphide ores are usually converted into oxides.
Answer
4
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q
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Answer
3
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q 15 and 16
Q.15. Why did gold and platinum always exist in free state?
Q.16. A metal is found to be present in vitamin B-12. Name the metal.
Answer
4
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q 7 8 and 9
Q7. What happen to the electrical conductivity when a metal is heated?
Q8. Which colour appears on the surface of aluminium when it is kept in air for sometimes?
Q9. Which property of copper and aluminium makes then suitable for making boilers and cooking.
Answer
3
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q 15 ans is given as A why so its not silver as both of them i-e gold and silver are less reactive.
Q..15. Metal always found in free state is
(A) Gold
(B) Silver
(C) Copper
(D) Sodium
Answer
1
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q 8 9 and 10
Answer
2
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q1 and 2 and pls give the reasons as well
Answer
2
Bhavyaa Trehan
Subject: Science
, asked on 12/2/18
Q 6 ,7and 8
Answer
2
Medha Bhattacharya
Subject: Science
, asked on 12/2/18
Someone plz ans this question
Q.15. (i) Give an example of a metal which can be easily cut with a knife.
(ii) How do metals react with oxygen and water? Give examples to explain.
Answer
3
Medha Bhattacharya
Subject: Science
, asked on 12/2/18
Someone plz ans this question
Q.9. (i) Name the metals that do not corrode easily.
(ii) An aluminium can is used to store ferrous sulphate solution. It is observed, in few days that holes appear in a can. Explain the observation and write the chemical equation in support of your answer.
Answer
3
Medha Bhattacharya
Subject: Science
, asked on 12/2/18
Someone plz ans this question
Q.11. Define the following terms :
(i) Mineral
(ii) Ore
(iii) Gangue
Answer
1
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What are you looking for?
(i) Aluminium used in construction of air crafts.
(ii) Lead in joining metals for electric works.
(iii) Copper used in household vessels.
Q 39. Iron nails are not rusted if kept in boiled distilled water for a long time. Explain.
(i) Metals replace hydrogen from dilute acids whereas non-metals do not.
(ii) Carbonate and sulphide ores are usually converted into oxides.
Q.15. Why did gold and platinum always exist in free state?
Q.16. A metal is found to be present in vitamin B-12. Name the metal.
Q7. What happen to the electrical conductivity when a metal is heated?
Q8. Which colour appears on the surface of aluminium when it is kept in air for sometimes?
Q9. Which property of copper and aluminium makes then suitable for making boilers and cooking.
Q..15. Metal always found in free state is
(A) Gold
(B) Silver
(C) Copper
(D) Sodium
Q.15. (i) Give an example of a metal which can be easily cut with a knife.
(ii) How do metals react with oxygen and water? Give examples to explain.
Q.9. (i) Name the metals that do not corrode easily.
(ii) An aluminium can is used to store ferrous sulphate solution. It is observed, in few days that holes appear in a can. Explain the observation and write the chemical equation in support of your answer.
Q.11. Define the following terms :
(i) Mineral
(ii) Ore
(iii) Gangue