Obtain an expression for the kinetic energy of the electrons in the Bohr.s model of hydrogen atom (Z - 1). Start from equating the electrostatic force with the centripetal force required and then use the quantisation condition for angular momentum.

Explanation

To derive the expression for the kinetic energy of electrons in the Bohr model of the hydrogen atom, we will follow these steps:

### Step 1: Equate Electrostatic Force and Centripetal Force
In the Bohr model, the electron is in a circular orbit around the nucleus (proton). The electrostatic force (Coulomb's law) provides the necessary centripetal force for the electron's circular motion.

The electrostatic force \( F_e \) between the electron and the nucleus is given by:
\[
F_e = \frac{k \cdot e^2}{r^2}
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