If ice floating on water in a vessel melts, the water level in the vessel . . . . . . . .

Correct Answer: B: does not change

Here's why the water level doesn't change when ice floating in water melts:

* Archimedes' Principle: An object floating in water displaces its own weight of water.
* Ice's Weight: The weight of the ice is exactly equal to the weight of the water it displaces when floating.
* Melting Ice: When the ice melts, it turns into water.
* Volume of Melted Ice: The volume of water produced by the melted ice is exactly the same as the volume of water the ice displaced when it was floating.
* Conclusion: Because the melted ice contributes the same volume as the water it initially displaced, the water level remains the same.