why does ice expand when frozen?

Question

when a solid is heated the mollecules expand and move apart in each stage, therefor when you freeze water, it should shrink as the mollecules get closer together to become a solid. anyone know why it expands instead?

Answer 1

Translated into english, the water molecule shape changes during the freezing process, and pushes away from other water molecules thus expanding.

From Wikipedia -

Generally, water expands when it freezes because of its molecular structure, in tandem with the unusual elasticity of the hydrogen bond and the particular lowest energy hexagonal crystal conformation that it adopts under standard conditions. That is, when water cools, it tries to stack in a crystalline lattice configuration that stretches the rotational and vibrational components of the bond, so that the effect is that each molecule of water is pushed further from each of its neighboring molecules. This effectively reduces the density ρ of water when ice is formed under standard conditions.

Answer 2

The primary reason that water expands when it freezes has to do with the shape of the molecules. Most molecules have specific shapes that will compact together quite well. Water molecules however don't, it's more of a "V" shape. The other factor is when they come close together via freezing, the hydrogen's face toward each other.

Think of it like the spokes of a wheel, at the center of a bike wheel the primary ring that holds the spokes in place are made up of oxygen atoms. The outer ring of metal is the hydrogen atoms, and the spokes themselves are the bonds that hold the hydrogen and oxygen atoms together.

Now try putting a bunch of those wheels together and see what happens, you start to see voids and spaces forming between 2 water molecules...it looks kind of like <>.

Now imagine a bunch of those together and it will show how water expands when frozen, because it's the closest the molecules can draw together, and why ice is less dense than water. Because the arrangement of the water molecules creates more volume with the same amount of mass, making it have a lower density than water.

Answer 3

Water {ice} expands because molecules spread apart when in a solid form. It's probably the only compound that expand when it's frozen;Liquid molecules are closer, therefore they move around more freely.As for water the bonding is such that the molecules end up farther apart in ice than water The fact that water expands when it freezes means that ice is less dense than water; therefore it floats in the said water.

Answer 4

it is due to the molecular structure of H2O. when the two Oxygen molecules attach to the Hydrogen molecule (O-H-O) they form a crescent moon shape. In it's liquid form, these molecules flow freely around each other. Yet when H2O freezes these molecules "line" up in a orderly fashion, forming something akin to a honey comb pattern, expanding the volume the molecules take up. Though, like all other substances, once the H2O is frozen, it also shrinks and takes up less volume the colder it gets.

Answer 5

The forces binding the water molecules cause the molecules to twist into a different orientation during freezing, forming a crystal lattice. Because of the peculiar shape of water molecules (they are sort of V-shaped rather than just simple spheres), the new orientation causes them to push each other a little farther apart than when they are in liquid form.

Answer 6

well rick b said

The forces binding the water molecules cause the molecules to twist into a different orientation during freezing, forming a crystal lattice. Because of the peculiar shape of water molecules (they are sort of V-shaped rather than just simple spheres), the new orientation causes them to push each other a little farther apart than when they are in liquid form.

it`s not so bad, well, if u wanna know more study about fractals http://en.wikipedia.org/wiki/Fractal

Answer 7

Just to be a little picky..... In the question is states that the heated molecules expand when heated.... They dont! The molecules vibrate when heated - the more 'energy' given, the more they vibrate. The space between the molecules increases thus causing expansion in the substance.

Answer 8

It isn't the ice that expands, it's the water . As water temperature drops, the water gets progressively denser until the temperature reaches 4° C, when it starts to expand and becomes less dense and consequently lighter. If this didn't happen, ice would start forming at the bottom of a mass of water, instead of, as we all know, at the top.

Answer 9

it is with the aid of a minimum of something regularly pointed out because of the fact the anomalous strengthen of water. between 0-4deg celsius, water expands. this is why ice floats on water and why livin organisms nonetheless stay in frozen lakes or different water bodies.

Answer 10

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