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Wavelength from a graph

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For the hydrogen spectrum, how do you find the wavelength (experimental value in nm) from a graph? I don't understand what exactly you are plotting and how to get the wavelength from the graph. For example, if your scale readings are:

Violet-4.5, Blue-5.0, Yellow-6.0, Red-6.6

The same question applies to the spectra of cations when you have different solutions such as LiCl and your scale readings are:

Red-6.8, Yellow-6.1, Blue 4.6

How do you find these wavelengths from the graph?

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Dear student,
Spectrum means power vs wavelength(or frequency). To make the graph simpler the indexes on 10 (e.g., 4.5*10^(-7) m ) are not shown in the graph, and it is ...

Solution Summary

This solution explains scales in graphs and how to find wavelengths using listed scales.

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