The atomic hydrogen emits a line spectrum consisting of various series. Which series of hydrogen atomic spectra is lying in the visible region?

The hydrogen emission spectrum consists of several series corresponding to transitions ending at different energy levels. The Lyman series (transitions to $$n = 1$$) lies in the ultraviolet region. The Paschen series (transitions to $$n = 3$$), Brackett series (transitions to $$n = 4$$), and higher series lie in the infrared region.

The Balmer series corresponds to transitions from higher energy levels ($$n = 3, 4, 5, \ldots$$) to $$n = 2$$. The wavelengths of the Balmer series range from about 365 nm to 656 nm, which falls in the visible region of the electromagnetic spectrum.

Therefore, the series lying in the visible region is the Balmer series.