Alright. So here we have an example problem that's asking why does ice float in liquid water? And we've got these four potential answer options down below. Now after reading through some of these answer options, there are a few that we can eliminate right off the bat such as option c here, which says that the ionic bonds between the molecules in ice prevent the ice from sinking. But of course, we know that water is not an ion because it does not have full charges.
It only has partial charges. So it's not an ion, which means that it cannot form ionic bonds. And so because it says ionic bonds here, we should have been able to eliminate answer option c right away. Now, answer option d here says, the lattice structure of ice causes it to be more dense than liquid water. But once again, recall from our last lesson video that solid ice is actually less dense, not more dense than liquid water.
And so for this reason right here we can eliminate answer option d. So now we're between either option a or option b, and notice option a says the high surface tension of liquid water makes the ice float, But even ice that penetrates the liquid surface and goes beyond, the surface tension, it breaks the surface tension, that ice that breaks the surface tension will still ultimately end up floating again. So it's not the surface tension that's allowing ice to float. And so option a, although it might be a tempting answer option, is not true. And so the real reason that ice floats on liquid water is because stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water.
And so because water molecules of ice are farther apart, it means that it is less dense, Solid ice is less dense than liquid water molecules, which are denser. And so things that are less dense will float. And so option b is going to be the correct answer for this example problem. And that concludes this example, so I'll see you all in our next video.