The Rydberg equation for the hydrogen atom is given by (1/λ) = RH (1/nf^2 - 1/ni^2)
Where RH is the hydrogenic Rydberg constant, 1.0974×10^7m^−1, nf and ni are the final and initial principal quantum numbers of the energy levels, respectively. (The transition is from ni to nf )
The Balmer series are emission lines associated with transitions ending at the n = 2 principal level.
What is the upper principal level that generates a transition at 656.3 nm?
(1nm=10^−9m)

the doppler effect is used by weather forecasters to measure 

moving clouds

part 1: describe the mass and the surface temperature of dwarf stars.

part 2: explain using complete sentences where on the hr diagram you would expect to find a dwarf star based on its physical properties.

part 1: the mass of a dwarf star is very small and the surface temperature of dwarf stars are high and they have the lowest absolute brightness.

part 2: on the hr diagram you would expect to find a dwarf star based on its physical properties at an absolute brightness of -2 to -4

hope this