Final answer:
The line spectrum from an Hg gas lamp is originated from mercury atoms absorbing light. When the mercury atoms in the lamp are excited and then decay to the ground state, they emit light at specific wavelengths, resulting in a line spectrum.
Step-by-step explanation:
The line spectrum from an Hg gas lamp is originated from mercury atoms absorbing light. The line spectrum from an Hg gas lamp is originated from mercury atoms absorbing light. When the mercury atoms in the lamp are excited and then decay to the ground state, they emit light at specific wavelengths, resulting in a line spectrum.
When an Hg gas lamp is electrically excited, neutral mercury atoms in the lamp are excited to higher energy states. As these atoms decay back to the ground state, they emit light at specific wavelengths, resulting in a line spectrum. The emission lines produced by the excited mercury atoms in the gas lamp are responsible for the characteristic colors observed.