Question 1 :
Identify the type of reaction: Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773 K to form ammonia gas.

Question 2 :
State TRUE or FALSE. New species may be formed if DNA undergoes significant changes in germ cells

Question 3 :
State TRUE or FALSE. Green plants get their food from organic compounds

Question 4 :
Property of the element : An element with variable (more than one) valency stored under water. Where would you locate the following element in the Periodic Table?

Question 5 :
Identify the type of reaction Limestone is heated strongly to form quicklime and carbondioxide gas is evolved

Question 7 :
The reactivity of a piece of aluminium metal decreases if it is dipped in $HNO_3$ . State TRUE or FALSE.

Question 8 :
In human beings, the statistical probability of getting either a male or female child is 50 : 50. The ratio of male gametes containing X chromosome and those containing Y chromosome is 50 : 50, the statistical possibility of male or a female infant is also 50 : 50.

Question 9 :
Direct current always flows in one direction but the alternating current reverses its direction periodically. Is the statement given above about the difference between the direct and alternating current correct?

Question 10 :
What steps would you suggest to minimise environmental pollution caused by burning of fossil fuels?

Question 11 :
You are given the balls and sticks models of six carbon atoms and fourteen hydrogen atoms and sufficient number of sticks. In how many ways one can join the models of six carbon atoms and fourteen hydrogen atoms to form different molecules of $C_6H_{14}$ ?

Question 12 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d04273b230584979b85.jpg' /> In the above image, current flowing through 4 Ω resistor in Ampere is ?

Question 13 :
Sudha finds out that the sharp image of the window pane of her science laboratory is formed at a distance of 15 cm from the lens. She now tries to focus the building visible to her outside the window instead of the window pane without disturbing the lens. What is the approximate focal length of this lens ?

Question 14 :
State TRUE or FALSE. New species may be formed if mating does not take place.

Question 16 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d08273b230584979b8a.jpg' /> In the above image, the correct sequence of anaerobic reactions in yeast is ?

Question 17 :
In the context of conservation of natural resources, explain the term reduce.

Question 18 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b19d0d273b230584979b8f.jpg' /> In the above image, a constant current flows in a horizontal wire in the plane of the paper from east to west. The direction of magnetic field at a point will be North to South .............

Question 19 :
In the context of conservation of natural resources, explain the term recycle.

Question 20 :
Reproduction is essentially a phenomenon that is not for survival of an individual but for continuation of a species. State TRUE or FALSE.