Which of the following has similar spectrum as that of `Li^(+)` :-

Options

A. H
B. `Na^(10+)`
C. He
D. `He^(+)`

Answer

To determine which of the following has a similar spectrum to that of \( \text{Li}^+ \), we need to analyze the electronic configuration of \( \text{Li}^+ \) and compare it with the options provided.

### Step-by-Step Solution:

1. **Identify the Electronic Configuration of Lithium (Li)**:
- Lithium (Li) has an atomic number of 3, which means it has 3 electrons.
- The electronic configuration of Li is \( 1s^2 2s^1 \).

2. **Determine the Configuration of \( \text{Li}^+ \)**:
- \( \text{Li}^+ \) means that lithium has lost one electron.
- Therefore, the electronic configuration of \( \text{Li}^+ \) becomes \( 1s^2 \).

3. **Identify the Electron Configuration of Other Elements**:
- We need to find which of the given options has the same electronic configuration as \( 1s^2 \).
- The element with the configuration \( 1s^2 \) is Helium (He), which has an atomic number of 2.

4. **Conclusion**:
- Since \( \text{Li}^+ \) has the configuration \( 1s^2 \), and Helium also has the configuration \( 1s^2 \), they will have similar spectra.
- Therefore, the answer is Helium (He).

### Final Answer:
The element that has a similar spectrum to that of \( \text{Li}^+ \) is **Helium (He)**.