Who is known as the father of Indian Bryology?

$A$ person who tosses an unbiased coin gains two points for turning up a head and loses one point for a tail. If three coins are tossed and the total score $X$ is observed,then the range of $X$ is

Among the following compounds,which one is not responsible for the depletion of the ozone layer?

$A$ piece of iron is heated in a flame. It first becomes dull red, then becomes reddish yellow, and finally turns to white hot. The correct explanation for the above observation is possible by using:

Which of the following statements does not form part of Bohr's model of the hydrogen atom?

Assertion : Between any two given energy levels,the number of absorption transitions is always less than the number of emission transitions.
Reason : Absorption transitions start from the lowest energy level only and may end at any higher energy level. But emission transitions may start from any higher energy level and end at any energy level below it.