(c) Coulombic force on electron, $F_{e} = a_{e}m_{e}\ $
Similarly, for proton $F_{p} = a_{p}m_{p}$
Here $F_{e} = F_{p}$
$\therefore\ \ \ \ \ \ \ a_{e}m_{e} = a_{P}m_{p}$
$\Longrightarrow \ \ \ \ \ \ \ \ \ \ a_{p} = \frac{a_{e}m_{e}}{m_{p}}$
$\ \ \ \ \ \ \ \ \ = \frac{\left( 2.5 \times 10^{22} \right)(9.1 \times 10^{- 31})}{1.6 \times 10^{- 27}}$
$\ \ \ \ \ \ \ \ \ = 1.42 \times 10^{19}$
$= 1.5 \times 10^{19}$ m/$s^{2}$