Water is the only common substance that when you freeze it, it's volume INCREASES.
When the pipe originally held the "all full" volume and the the water expanded, it put a tremendous amount of pressure on the pipe. Enough pressure and the pipe would burst.
Answer:
Decrease
Explanation:
Since the speed in which the gas molecules are faster as they are heated, they fly around in the container and logically, it is harder to insert a moving object into water than something more stationary or slower.
Silicon, it's bring brother would be the prime candidate, although its compounds are notably different from those of carbon.