Explain the meaning of ground state and excited state of an atom?

Estimate the ratio of the wavelength associated with the electron orbiting around the nucleus in the ground and first excited state of hydrogen atom.

A set of atoms in an excited state decays

State and explain the law of mass action.

Explain the term state function.

The hydrogen atom in the ground state is excited by mass of monochromatic radiations of wavelength lambda Å . The resulting spectrum consists of maximum 15 different lines . What is the value of lambda ? ( R_H = 109737 cm^(-1)) .

State and explain the terms flux and slag.

What is the ratio of radii of the orbits corresponding to first excited state and ground state in a hydrogen atom?