A gas of monoatomic hydrogen is bombarded with a steam of electrons th...
Explanation:
When a gas is bombarded with a stream of electrons, it can undergo various processes such as ionization, excitation, and de-excitation. These processes result in the emission of electromagnetic radiation, which can be observed as an emission spectrum. The emission spectrum consists of a series of lines corresponding to different energy transitions within the gas.
The energy of the emitted radiation is directly related to the energy difference between the initial and final states of the gas atoms or molecules. Different energy transitions result in different series of lines in the emission spectrum.
In the case of hydrogen, the energy transitions are categorized into several series, such as the Lyman series, Balmer series, Paschen series, and Pfund series. Each series corresponds to a specific range of energy transitions.
The Lyman series corresponds to energy transitions that involve the ground state (n=1) as the final state. The Balmer series corresponds to transitions to the first excited state (n=2) as the final state. The Paschen series corresponds to transitions to the second excited state (n=3) as the final state. The Pfund series corresponds to transitions to the third excited state (n=4) as the final state.
In this case, if no line of the Lyman series is observed in the emission spectrum, it means that there are no energy transitions involving the ground state (n=1) as the final state. This can occur if the energy of the bombarding electrons is not sufficient to excite hydrogen atoms to the first excited state (n=2) or higher.
Explanation:
- The energy transitions in hydrogen gas result in the emission of electromagnetic radiation, which can be observed as an emission spectrum.
- The emission spectrum consists of a series of lines corresponding to different energy transitions within the gas.
- Different series of lines correspond to different energy transitions in hydrogen, such as the Lyman series, Balmer series, Paschen series, and Pfund series.
- The Lyman series corresponds to energy transitions involving the ground state (n=1) as the final state.
- If no line of the Lyman series is observed in the emission spectrum, it means that there are no energy transitions involving the ground state as the final state.
- This can occur if the energy of the bombarding electrons is not sufficient to excite hydrogen atoms to the first excited state (n=2) or higher.
- In this case, the steam of electrons accelerated through a potential difference of 12.75 V may not have enough energy to excite hydrogen atoms to the first excited state or higher.
- Therefore, no line of the Lyman series would be observed in the emission spectrum.