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:
the frequency of photons 
Explanation:
Given: first ionization energy of 1000 kJ/mol.
No. of moles of sulfur = 1 mole

We know that plank's constant

Let the frequency of photons be ν
Also we know that ΔE = hν
this implies ν = ΔE/h


Hence, the frequency of photons 
I believe the answer is C
Water
Water is a compound because it is made from more than one kind of element (oxygen and hydrogen).
After 100years, sample is 250g
After 200 years, sample is 125g
After 300years, sample is 62.5 g