Answer:
The answer you would be looking for is option A because all of the other options are either false, or beneficial to us, and i took the test. Thanks
Explanation:
The equation that scientists could use to find the wavelength of the emission lines of the hydrogen atom would be that of Balmer.
The wavelength of the emission lines of the hydrogen atom can be derived using the Balmer series:
1/λ 
Where λ = wavelength,
= Rydberg constant, and n = level of the original orbital.
The equation becomes applicable in getting the wavelength of emitted light when electrons in hydrogen atoms transition from higher (n) orbital to lower orbital (2) levels.
More on the Balmer series can be found here: brainly.com/question/5295294
The inner core us the densest
1. Dmitri created groups of 3
2. John Newlands arranged the elements
3. Antoine Lavoisier divided them into catagories
4. Johann used patterns
hope this helped :)