Excited hydrogen atoms emit radiation in which region(s) of the electromagnetic spectrum?

• A. Only the infrared region
• B. Ultraviolet, visible, and infrared regions
• C. Only the visible region
• D. Only the ultraviolet region

Answer: (B)

Verified step by step guidance

1. Understand that when hydrogen atoms are excited, their electrons move to higher energy levels and then return to lower energy levels, emitting photons in the process.
2. Recall that the energy difference between these levels determines the wavelength (and thus the region) of the emitted radiation, using the formula \(E = h \nu = \frac{hc}{\lambda}\), where \(E\) is energy, \(h\) is Planck's constant, \(\nu\) is frequency, \(c\) is the speed of light, and \(\lambda\) is wavelength.
3. Recognize that the hydrogen emission spectrum consists of several series (Lyman, Balmer, Paschen, etc.), each corresponding to electron transitions ending at a specific energy level.
4. Note that the Lyman series transitions emit photons in the ultraviolet region, the Balmer series in the visible region, and the Paschen series in the infrared region of the electromagnetic spectrum.
5. Conclude that excited hydrogen atoms emit radiation across multiple regions: ultraviolet, visible, and infrared, depending on the electron transitions involved.