To solve the question regarding the emission of light when an electron in an excited hydrogen atom drops from higher energy levels (n = 4, 5, 6) to the ground state (n = 1), we can follow these steps:
### Step-by-Step Solution:
1. **Understand Energy Levels**: In a hydrogen atom, the energy levels are quantized and represented by the principal quantum number \( n \). The ground state is \( n = 1 \), and higher excited states are \( n = 2, 3, 4, 5, \) and \( 6 \).
2. **Identify the Transitions**: The question specifies transitions from \( n = 4, 5, \) and \( 6 \) to \( n = 1 \). We need to analyze the energy difference for each transition:
- Transition from \( n = 4 \) to \( n = 1 \)
- Transition from \( n = 5 \) to \( n = 1 \)
- Transition from \( n = 6 \) to \( n = 1 \)
3. **Calculate Energy of Emission**: The energy of the emitted photon can be calculated using the formula:
\[
E = -R_H \left( \frac{1}{n_f^2} - \frac{1}{n_i^2} \right)
\]
where \( R_H \) is the Rydberg constant (\( 13.6 \, \text{eV} \)), \( n_f \) is the final energy level (1 in this case), and \( n_i \) is the initial energy level (4, 5, or 6).
4. **Determine the Wavelength and Type of Light**: The energy of the emitted light can be related to its wavelength using the equation:
\[
E = \frac{hc}{\lambda}
\]
where \( h \) is Planck's constant and \( c \) is the speed of light. Depending on the energy calculated, we can determine whether the emitted light falls in the ultraviolet (UV), visible, infrared (IR), or radio wave range.
5. **Analyze the Results**:
- For transitions from \( n = 4 \), \( n = 5 \), and \( n = 6 \) to \( n = 1 \), the energies will be high enough to emit UV light since these transitions involve significant energy differences.
6. **Conclusion**: Since all transitions from \( n = 4, 5, \) and \( 6 \) to \( n = 1 \) result in the emission of light in the ultraviolet range, the correct answer to the question is **UV light**.
### Final Answer:
The emission of light when an electron drops from \( n = 4, 5, 6 \) to \( n = 1 \) in an excited hydrogen atom is **UV light**.
