Question

The first spectral line of sodium atom is 5890 Å. Then the first excitation potential of sodium is –

• A. 3.7 V
• B. 2.1 V
• C. 10.2 V
• D. 4.1 V

Answer 1

Answer: (B)

2.1 V

Answer 2

DE = eV = $\frac{hc}{\lambda}$ ̃ V = $\frac{hc}{e\lambda}$