Questions

Number of spectral lines from a state n to ground state is

                   n(n-1)/2 = 6

A solid sinks in a liquid if its density is greater than that of the liquid. if less, it floats

National Science Day is celebrated in India on 28 February each year to mark the discovery of the Raman effect by Indian physicist Sir Chandrashekhara Venkata Raman on 28 February 1928.

When atoms react they do so in order to reach the lowest energy, which is the most stable. The electrons orbitals will overlap in the way that reduces the energy the most. Orbitals of similar energy will produce the greatest stabilisation.The answer you gave isn't the whole story, it depends what species is reacting with what. The effective nuclear charge on the atom will affect the energy of the valance electrons.

Hence, the reactivity of an atom arises from the existence of unpaired electrons in the valence shell.

The book “Indira Gandhi – A life in Nature”, was launched by Congress president Sonia Gandhi at the Indira Gandhi Memorial in the presence of former ministers, bureaucrats and environmentalists who worked closely with her to frame some of country’s landmarks wildlife and environment laws. Renowned mountaineer Capt Manmohan Singh Kohli recalled how Gandhi once told him “please call me as a daughter of the mountains”. The book has been written by former Union minister Jairam Ramesh and it has been published by Simon & Schuster.