The simple Bohr model cannot be directly applied to calculate the energy levels of an atom with many electrons. This is because

Options

A. of screening effects
B. the force between the nucleus and an electron will no longer be given by Coulomb's law.
C. of the electrons not being subject to central force
D. of the electrons colliding with each other.

Answer

C

Explanation

Each electron will not only interact with positively charged nucleus (which provides the central force) but also with the other electrons (i.e. we have to take electron-electron interaction), and hence electron.s are not subject to central force.