Question

An electronic transition in hydrogen atom results - in the formation of $Ha$ line of hydrogen in Lyman series, the energies associated with the electron in each of the orbits involved in the transition (in $kcalmo{l}^{-1}$) are

• A. -313.6, - 34.84
• B. -313.6, -78.4
• C. -78.4, - 34.84
• D. -78.4, -19.6

Answer 1

Answer: (B)

Energy of electron in $n^{\text{th }}$ an orbit in hydrogen atom in $kCal/mol$ is given as:
$E_n=-313.6\times \left(1/n^2\right)kCal/mol$
$H_{\alpha }$ line in Lyman series of Hydrogen corresponds to the first line of transition from
$2\to 1$
Therefore, energy of electron in the orbit $1$ and $2$ are:
$E_1=-313.6\times \left(1/1^2\right)=-313.6kCal/mol$
$E_2=-313.6\times \left(1/2^2\right)=-78.4kCal/mol$