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Scum floats on the surface of the water ...

Scum floats on the surface of the water because

A

The density of cells is more than that of water

B

Oxygen accumulates in it

C

`H_(2)S` accumulates in it

D

It generates methane gas

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question "Scum floats on the surface of the water because", we need to analyze the options provided and understand the properties of scum and its interaction with water. ### Step-by-Step Solution: 1. **Understanding Scum**: Scum refers to a layer of dirt, froth, or organic matter that forms on the surface of water. It is often composed of various microorganisms, organic debris, and gases. 2. **Analyzing the Options**: - **Option 1**: "The density of cells is more than that of water." - This option is incorrect because the density of the materials in scum is generally less than that of water, which would not allow it to float. - **Option 2**: "Oxygen accumulates in it." - This option is correct. Scum can trap air and oxygen in microbubbles, which decreases its overall density and allows it to float on the water's surface. - **Option 3**: "Hydrogen sulfides accumulate in it." - This option is incorrect. While hydrogen sulfide may be present in some water bodies, it does not contribute to the floating of scum. - **Option 4**: "It generates methane gas." - This option is also incorrect. Although some decomposition processes can produce methane, it is not the primary reason scum floats. 3. **Conclusion**: The correct answer to the question is **Option 2: Oxygen accumulates in it**. The trapped oxygen in microbubbles reduces the density of the scum, allowing it to float on the surface of the water.
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