Final answer:
The statement "hydrogen emission spectrum has a line that shows up in the UV spectrum and cannot be seen" is true. The Lyman series, in particular, falls in the UV region, while the Balmer series is visible.
Step-by-step explanation:
The question refers to whether a line in the hydrogen emission spectrum shows up in the UV spectrum and cannot be seen. The answer is true. Hydrogen gas can indeed emit light that falls into the ultraviolet (UV) range of the electromagnetic spectrum, which is not visible to the human eye.
The hydrogen emission spectrum consists of several series of lines, including the Lyman series, which are predominantly in the UV region. These lines correspond to electronic transitions in the hydrogen atom and represent the energy releases when an electron falls from a higher energy level to a lower one. The most well-known of these series, the Balmer series, falls within the visible spectrum and is recognizable by its distinct lines, but not all lines of the hydrogen spectrum are within the visible range. Such is the case for the Lyman series, which falls in the UV region.
These series and the corresponding wavelengths can be calculated using specific formulas and are of great importance in the fields of physics and astronomy as they provide vital information about the structure of the hydrogen atom and the energies involved in electron transitions.