This may be a dumb question (probably I skipped the Chem. class that explained this), but since heat causes things to expand, and cold causes them to contract, why does water expand when you freeze it?
As explained to me by my 3.8 average physics major sister:
When water freezes is forms a “lattice” or crystaline structure. This forms spaces between the molecules and expands the volume. It is one of the few substances that takes up more volume as a solid.
Is it my foggy memory or is it true: cast iron is another rare substance that takes less volume when liquid?
Peace
Previous threads addressing the subject:
I’m not readily recalling a liquid form of cast iron. Perhaps you meant molten iron?
Beatle, I mean that cast iron, like ice, takes more volume when it is solid, compared with its liquid form, whatever you call it. If this is clear , do you know the answer?
Peace
Cast Iron liquid and solid density includes this line:
which I read as saying the liquid form is less dense than the solid, which would make it like everything else except water/ice. That page is a bit obtuse. You through me with your mention of liquid cast iron because, if it’s liquid, i.e., molten, it’s not cast, yet.
Beatle, sorry for the confusion. As I said, my memory is rusty (no pun intended), but somehow I remembered it specifically about cast iron. Probably, I should’ve said “iron”.
From that page, it looks like any iron is less dense liquid than solid, which will cause solid iron sink. Is this the case?
Peace
Barring surface tension effects and/or presence of a slag coating, the solid should sink if it is denser.