Processes of (

The significance of $(n-n')$-mixing processes in $H^*(n)+H(1$s) collisions, for the principal quantum number $n \ge 4$, in the Solar photosphere and lower chromosphere has been investigated. These processes have been treated by the mechanism of resonant energy exchange within the electron component of the considered collision system. These processes must have significant influence in comparison with corresponding electron-atom collision processes on the populations of hydrogen Rydberg atoms in weakly ionized layers of the Solar atmosphere (ionization degree of the order of 10-4). From the results obtained it follows that the examined $(n-n')$-mixing processes have to be included in any modelling and investigation of Solar plasma, especially in the region of the temperature minimum in the Solar photosphere.