Questions

Aravalli seperates the valleys of Luni and Mahi while Vindhyas seperate the valleys of Mahi and Narmada

The stability of the ions is determined by the energy of the lone pairs. Carbon has the least effective nuclear charge (Zeff) and so the lone pair on the CH3− ion has the highest energy, making it the least stable ion and so the strongest base. The Zeff increases as we move across the period until we get to fluorine which has the greatest Zeff and so its lone pairs have the lowest energy, making F− the least basic ion.

In order of decreasing basicity they are ranked LiCH3 > LiNH2 > LiOH > LiF. We are dealing with the ions F−, OH−, NH2− and CH3− and so the factor which influences their basicity is the stability of the ion compared to its conjugate acid.

Sound intensity is measured in decibels(db). Sound pollution above 120 db becomes more hazardous and have adverse affects on human life. 

The given statement implies that 64 Squares on Carrom Board.

Plants are of different types. Some grow well and then produce fruits before they die. In other words they fruit only once in their life. Such plants are said to be monocarpic. Other plants produce fruits every season. These are called polycarpic plants.