Bohr's atomic model can expalin the spectrum of

Options

A. Hydrogen atomic only
B. Atoms or ions which are unielectron
C. Atoms or ions which have only two electrons
D. Hydrogen molecule

Explanation

To solve the question "Bohr's atomic model can explain the spectrum of," we need to analyze the options provided and understand the implications of Bohr's atomic model.

### Step-by-Step Solution:

1. **Understanding Bohr's Model**:
- Bohr's atomic model was proposed by Niels Bohr in 1913. It describes the behavior of electrons in atoms and explains how they occupy discrete energy levels or orbits around the nucleus.

2. **Identifying Hydrogen-like Species**:
- Bohr's model is particularly effective for hydrogen and hydrogen-like species. Hydrogen-like species are atoms or ions that have only one electron. Examples include He⁺, Li²⁺, and other ions with a single electron.

3. **Evaluating the Options**:
- **Option 1**: Hydrogen atom only - This is incorrect because Bohr's model applies to more than just hydrogen; it also applies to hydrogen-like ions.
- **Option 2**: Atoms or ions which are unielectron - This is correct because Bohr's model can explain the spectra of any atom or ion that has only one electron.
- **Option 3**: Atoms or ions which have only two electrons - This is incorrect because Bohr's model does not apply to multi-electron systems effectively.
- **Option 4**: Hydrogen molecule - This is absolutely incorrect as the model does not apply to molecules.

4. **Conclusion**:
- The correct answer is **Option 2**: Atoms or ions which are unielectron.

### Final Answer:
Bohr's atomic model can explain the spectrum of atoms or ions which are unielectron.

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