Balmer and Lyman series

[Sydney Takeda 2I]

Can someone explain this equation?

[Kelsey Warren 1I]

I'm not 100% sure, but it's derived from the equation in lecture today, E=-hR/(n^2). If you substitute E=hv, then you can divide both sides by h to get rid of Planck's constant, as in the equation you posted. Besides that, I'd guess that you would use it to find the frequency of a photon emitted from an electron's transition from one energy level, n1, to a lower energy level, n2.

[505095972]

I think it is basically the same equation, but it is just trying to determine the change in frequency when it is excited, rather than the frequency at a certain instant.

[Cienna Henry 1J]

What do the ns signify in this equation?