Question

The Wave number of first ;line of balmer series of hydrogen is ${15200cm}^{-1}$. The wave number of the first line ${Li}^{2+}$ ion is?

• A. ${15200cm}^{-1}$
• B. ${60800cm}^{-1}$
• C. ${76000cm}^{-1}$
• D. ${136800cm}^{-1}$

Answer 1

The correct option is D ${136800cm}^{-1}$

As we know the energy of constant state for hydrogen species like $L{i}^{2+}$ are multiple of integral type of $z^2$ times the energy of hydrogen atom in stationary form.

Hence the wave number of first line of ion= $3^2\times 15200$

$\therefore$ Wave number $=136800c{m}^{-1}$