what allows water to change to all three states (liquid,gas,solid)
Hmmm! I'm far from being a science teacher, but I often change water (a liquid) into a gas and a solid in my kitchen.
Pressure and/or temperature depending on where you are on the phase diagram.
There is an example of the water phase diagram here:
http://en.wikipedia.org/wiki/Phase_diagram
Water can change to all three states, liquid, gas, and solid, due to its unique molecular structure and the interaction forces between its molecules.
To understand this process, we need to have a basic understanding of the concept of states of matter. Matter can exist in three main states: solid, liquid, and gas. These states depend on the arrangement, movement, and energy levels of the particles (atoms, ions, or molecules) that make up the substance.
In the case of water, it is made up of molecules consisting of two hydrogen atoms bonded to one oxygen atom, resulting in the chemical formula H2O. The shape of the water molecule, called a bent or V-shape, gives rise to its unique properties.
1. Liquid state: In the liquid state, water molecules are relatively close together, but not tightly packed. The hydrogen bonds between neighboring water molecules are strong enough to keep them loosely connected. This allows water to flow and take the shape of its container, making it a liquid.
2. Gas state: When water molecules gain enough energy, typically in the form of heat, they overcome the hydrogen bonding forces holding them together. This energy disrupts the intermolecular bonding, causing the molecules to move more freely and independently. The individual water molecules then escape from the liquid phase and become water vapor in the gas state. This process is called evaporation or vaporization.
3. Solid state: At lower temperatures, water molecules lose energy and move slower. This reduction in energy allows the hydrogen bonds between the water molecules to become stronger, causing them to arrange in a highly organized structure. This results in the formation of a solid state, commonly known as ice. In the solid state, water molecules are arranged in a regular pattern, with each molecule being held in place by multiple hydrogen bonds.
To summarize, water can change to different states due to the interplay between the energy levels of its molecules and the strength of the hydrogen bonds. Increasing energy and breaking these bonds leads to the transition from liquid to gas, while decreasing energy and strengthening these bonds leads to the transition from liquid to solid.