(c) $E = E_{3} - E_{1} = - \frac{13.6}{3^{2}}—\left( - \frac{13.6}{1^{2}} \right)$ $E = - 1.51 + 13.6 = 12.09\ eV$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.