6. The fact that ice is less dense than water is related to the fact that
ice has a molecular structure that is an open framework held together by hydrogen bonds
the molecules of ice are held to each other by covalent bonding
ice has a molecular structure in which water molecules are arranged randomly
the molecular structure of ice is much less orderly than that of water

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.