Assertion : Absorption spectrum consists of some bright lines separated by dark spaces.
Reason : Emission spectrum consists of dark lines.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understanding the Assertion
The assertion states that "Absorption spectrum consists of some bright lines separated by dark spaces."
- An absorption spectrum is created when light passes through a cooler gas or vapor. The gas absorbs specific wavelengths of light, resulting in dark lines appearing on an otherwise continuous spectrum. The bright lines mentioned in the assertion refer to the continuous spectrum of light that is transmitted through the gas, while the dark lines indicate the wavelengths that have been absorbed.

### Step 2: Understanding the Reason
The reason states that "Emission spectrum consists of dark lines."
- An emission spectrum is produced when a gas is heated or energized, causing it to emit light at specific wavelengths. This spectrum typically appears as bright lines on a dark background, not dark lines. Therefore, the statement in the reason is incorrect.

### Step 3: Conclusion
Based on the analysis:
- The assertion is **true** because absorption spectra do consist of bright lines (the transmitted light) with dark spaces (the absorbed wavelengths).
- The reason is **false** because the emission spectrum consists of bright lines on a dark background, not dark lines.

### Final Answer
Thus, the assertion is true, but the reason is false.

---