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Class 6	Science Mathematics Social Science	English Hindi Computer
Class 7	Science Mathematics Social Science	English Hindi Computer
Class 8	Science Mathematics Social Science	English Hindi Computer
Class 9	Science Mathematics Social Science	English Hindi Computer
Class 10	Science Math Social Science	English Hindi Computer
Class 11	Physics Chemistry Biology	Mathematics English Economics
Class 12	Physics Chemistry Biology	Mathematics English Economics
Class 5	EVS
College Entrance	Jamia Millia Islamia Aligarh Muslim University Banaras Hindu University

2019

Q21
What is water harvesting? List two main advantages associated with water harvesting at the community level. Write two causes for the failure of sustained availability of groundwater.

Solution

Q22
(a) List in tabular form three chemical properties on the basis which we can differentiate between a metal and non-metal.

Solution

Q23
(b) Give reasons for the following:
(i) Most metals conduct electricity well.

Solution

Q24
(b) Give reasons for the following:
(ii) The reaction of iron (III) oxide [Fe₂O₃] with heated aluminium is used to join cracked machine parts.

Solution

Q25
Write the chemical formula and name of the compound which is the active ingredient of all alcoholic drinks. List its two uses. Write chemical equation and name of the product formed when this compound reacts with -
(i) sodium metal
(ii) hot concentrated sulphuric acid

Solution

Q26
What is methane? Draw its electron dot structure. Name the type of bonds formed in this compound. Why are such compounds:
(i) poor conductors of electricity? and
(ii) have low melting and boiling points?
What happens when this compound bums in oxygen?

Solution

Q27
Define pollination. Explain the different types of pollination. List two agents of pollination? How does suitable pollination lead to fertilization?

Solution

Q28
<p>(a) Identify the given diagram. Name the part 1 to 5.<img alt="" src="https://imagedelivery.net/HpP6TwyM91IVKvXTR1TJrw/a5bafd54-2131-4c84-053f-9961665fb200/public" /></p>

Solution

Q29
(b) What is contraception? List three advantages of adopting contraceptive measures.

Solution

Q30
An object is placed at a distance of 60 cm from a concave lens of focal length 30 cm.
(i) Use lens formula to find the distance of the image from the lens.

Solution

Subjects

2019

Q21 What is water harvesting? List two main advantages associated with water harvesting at the community level. Write two causes for the failure of sustained availability of groundwater.

Solution

Q22 (a) List in tabular form three chemical properties on the basis which we can differentiate between a metal and non-metal.

Solution

Q23 (b) Give reasons for the following: (i) Most metals conduct electricity well.

Solution

Q24 (b) Give reasons for the following: (ii) The reaction of iron (III) oxide [Fe₂O₃] with heated aluminium is used to join cracked machine parts.

Solution

Q25 Write the chemical formula and name of the compound which is the active ingredient of all alcoholic drinks. List its two uses. Write chemical equation and name of the product formed when this compound reacts with - (i) sodium metal (ii) hot concentrated sulphuric acid

Solution

Q26 What is methane? Draw its electron dot structure. Name the type of bonds formed in this compound. Why are such compounds: (i) poor conductors of electricity? and (ii) have low melting and boiling points? What happens when this compound bums in oxygen?

Solution

Q27 Define pollination. Explain the different types of pollination. List two agents of pollination? How does suitable pollination lead to fertilization?

Solution

Q28

Solution

Q29 (b) What is contraception? List three advantages of adopting contraceptive measures.

Solution

Q30 An object is placed at a distance of 60 cm from a concave lens of focal length 30 cm. (i) Use lens formula to find the distance of the image from the lens.

Solution

Subjects

Q21
What is water harvesting? List two main advantages associated with water harvesting at the community level. Write two causes for the failure of sustained availability of groundwater.

Q22
(a) List in tabular form three chemical properties on the basis which we can differentiate between a metal and non-metal.

Q23
(b) Give reasons for the following:
(i) Most metals conduct electricity well.

Q24
(b) Give reasons for the following:
(ii) The reaction of iron (III) oxide [Fe₂O₃] with heated aluminium is used to join cracked machine parts.

Q25
Write the chemical formula and name of the compound which is the active ingredient of all alcoholic drinks. List its two uses. Write chemical equation and name of the product formed when this compound reacts with -
(i) sodium metal
(ii) hot concentrated sulphuric acid

Q26
What is methane? Draw its electron dot structure. Name the type of bonds formed in this compound. Why are such compounds:
(i) poor conductors of electricity? and
(ii) have low melting and boiling points?
What happens when this compound bums in oxygen?

Q27
Define pollination. Explain the different types of pollination. List two agents of pollination? How does suitable pollination lead to fertilization?

Q28
<p>(a) Identify the given diagram. Name the part 1 to 5.<img alt="" src="https://imagedelivery.net/HpP6TwyM91IVKvXTR1TJrw/a5bafd54-2131-4c84-053f-9961665fb200/public" /></p>

Q29
(b) What is contraception? List three advantages of adopting contraceptive measures.

Q30
An object is placed at a distance of 60 cm from a concave lens of focal length 30 cm.
(i) Use lens formula to find the distance of the image from the lens.