An electron in the hydrogen atom makes a transition from an energy state of principal quantum number ni to the n = 2 state. if the photon emitted has a wavelength of 657 nm, what is the value of ni?

Explanation:

The Rydberg equation gives the wavelength λ for the transitions:

where

R= the Rydberg constant (1.0974 ×10⁷ m⁻¹) and

Data:

λ = 657 nm

Calculation:  

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).