Question

The dimensional formula for Rydberg constant is

• A. $\left[M^{0}L{T}^{-1}\right]$
• B. $\left[M^0{L}^{-1}{T}^0\right]$
• C. $\left[M^0{L}^0{T}^0\right]$
• D. $[MLT]$

Answer 1

Answer: (B)

$\frac{1}{\lambda }=R{Z}^2\left[\frac{1}{n_1^2}-\frac{1}{n_2^2}\right]$
$Z$ is atomic number, $n_1$ and $n_2$ are the principal quantum numbers,
Hence $[R]=\left[\frac{1}{\lambda }\right]=L^{-1};\Rightarrow [R]=\left[M^0{L}^{-1}{T}^0\right]$