From Lyman series of Pfund series, frequency___________A. IncreaseB. DecreaseC. Increase or decreaseD. No change

The Lyman series and the Pfund series are two different series of spectral lines in the hydrogen atom's emission spectrum. The Lyman series corresponds to transitions of electrons to the n = 1 energy level, while the Pfund series corresponds to transitions to the n = 5 energy level. In both series, electrons are transitioning to lower energy levels.

The energy of an electron in a hydrogen atom is given by the equation:

E = -13.6 eV / n^2

Where E is the energy of the electron, and n is the principal quantum number.

For the Lyman series, n starts at 2 and goes to 1, so the transitions involve higher initial energy levels (n = 2) and lower final energy levels (n = 1). For the Pfund series, n starts at 6 and goes to 5, so the transitions also involve higher initial energy levels (n = 6) and lower final energy levels (n = 5).

Since both series involve transitions to lower energy levels, the frequency of the emitted radiation in both the Lyman and Pfund series will increase. Therefore, the answer is:

A. Increase