Explain the rule according to which electrons are filled in various energy levels.

Answer the following questions: (i) (1) State Hund.s rule of maximum multiplicity. (2) Name the principle by which Electrons are filled in various orbitals in the increasing order of energies and fill up the orbitals of lower energy first.

Four electrons in an atom have the set of quantum numbers as given below. Which electron is at the highest energy level ?

Summarise the rules for writing of distribution of electrons in various shells for the first eighteen elements.

What is the Bohr-Bury scheme of electronic configuration? Write down the rules that are observed according to the scheme for writing the number of electrons in different energy levels or shells.

Explain the various stages of interphase.

Hydrogen atom: The electronic ground state of hydrogen atom contains one electron in the first orbit. If sufficient energy is provided, this electron can be promoted to higher energy levels. The electronic energy of a hydrogen-like species (any atom//ions with nuclear charge Z and one electron) can be given as E_(n)=-(R_(H)Z^(2))/(n^(2)) where R_(H)= "Rydberg constant," n= "principal quantum number" The energy required to promote the ground state electron of H-atom to the first excited state is: When an electron returns from a higher energy level to a lower energy level, energy is given out in the form of UV//Visible radiation.

The correct expression derived for the energy of an electron in the n^(th) energy level is for H-atom :

Explain various parts of a seed.

An electron is excited to fourth energy level in an atom. It will

Choose the pair in which after filling of electron , energy sequence is reversed