Statement-1 : The Bohr's model cannot differentiate between the spectra of hydrogen and deuterium.
and
Statement-2 : The Bohr's model considers the nucleus as infinitely massive in comparsion to the orbiting electrons.

Options

A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-3
B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-3
C. Statement-1 is True, Statement-2 is False.
D. Statement-1 is False, Statement-2 is True.

Answer

To analyze the statements, we will break down the reasoning behind each statement step by step.

### Step 1: Understanding Statement 1
- **Statement 1** claims that the Bohr's model cannot differentiate between the spectra of hydrogen and deuterium.
- Hydrogen (H) has one proton and no neutrons, while deuterium (D) has one proton and one neutron.
- The atomic number (number of protons) for both is the same (1), which means the charge of the nucleus is identical (+1e).
- The spectral lines depend on the charge of the nucleus and the energy levels of the electrons, which are determined by the Coulombic attraction between the nucleus and the electron.

**Conclusion for Step 1**: Since both hydrogen and deuterium have the same nuclear charge, their spectra will be the same according to Bohr's model.

### Step 2: Understanding Statement 2
- **Statement 2** states that the Bohr's model considers the nucleus as infinitely massive compared to the orbiting electrons.
- In the Bohr model, the nucleus is treated as a fixed point due to its large mass relative to the electron.
- This assumption allows us to ignore the motion of the nucleus and focus solely on the motion of the electron around it.
- The Coulomb force (the electrostatic force between the positively charged nucleus and the negatively charged electron) is the primary force considered in the model.

**Conclusion for Step 2**: The assumption of an infinitely massive nucleus simplifies the calculations and is a valid approximation for the behavior of electrons in atoms.

### Final Conclusion
- **Statement 1** is true: The Bohr model cannot differentiate between the spectra of hydrogen and deuterium.
- **Statement 2** is also true and correctly explains Statement 1: The model's assumption of an infinitely massive nucleus leads to the conclusion that the spectra are identical.

### Overall Answer
Both statements are true, and Statement 2 is the correct explanation for Statement 1.

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