Question

Consider the spectral line resulting from the transition from $n=2$ to $n=1,$ in atoms and ions given below. The shortest wavelength is produced by

• A. hydrogen atom
• B. deuterium atom
• C. singly ionized helium
• D. doubly ionized lithium

Answer 1

Answer: (D)

doubly ionized lithium

Answer 2

$\frac{1}{\lambda}=Z^{2} R\left(\frac{1}{1^{2}}-\frac{1}{2^{2}}\right)$ Hence, $\lambda$ is minimum when, $Z$ is maximum.