Plants usually show better growth when ammonium sulphate is added to the soil. How would you explain this behaviour?

Rana purchased a monumnet made of copper. It turned green after some time. As a student of chemistry, how would you explain this?

Name two metals which react violently with cold water. Write any three observtations you would make when such a metals is dropped into water. How would you identify the gas evolved if any, during the reaction?

Cut a transverse section of young stem of a plant from your school garden and observe it under the microscope. How would you ascertain whether it is a monocot stem or a dicot stem? Give reasons.

In the North East region of India, during the process of Jhum cultivation, forests are cleared by burning and left for regrowth after a year of cultivation. How would you explain the regrowth of forest in ecological term?

Following table shows the points of each player scored in four games: Now answer the following questions: B played in all the four games. How would you find the mean?

A sulphate salt of the group 2 element of the periodic table is a white, soft substance, which can be molded into different shapes by making its dough. When this compound is left in open for some time, it becomes a solid mass and cannot be used for molding purposes. Identify the sulphate salt and why does the show such a behaviour? give one reaciton involved.