This is all down to the intermolecular bonds and kinetic energy of each of the individual molecules.
In a liquid, each of the molecules will have more energy, and so will be able to break more intermolecular bonds (Allowing more movement of each of the molecules), and so meaning the molecules will be able to move much further apart.
Solids have much less energy, and don't have enough energy to break any of their intermolecular bonds. This means they all remain bonded to each other, and so will not be able to move.
The above is all generalised, and I've ignored a lot of the exceptions.
Sorry if I've messed up anywhere, too. I'm pretty tired right now.
Water has a lower density as a solid than it does as a liquid. In the vast majority of substances are denser as solids than as liquids.
luiquid is the most compact state of matter
There's no technical golden rule - water is denser than ice due to the bonding in its liquid phase, and some metals are denser in liquid form. Water is denser than certain other solids, including certain plastics and styrofoam. One variant of the material 'Aerogel' can even be made to be less dense than the atmosphere itself, a gas.
Gases the most, then liquids. Solids generally don't diffuse.
At room temperature most metals are solids. They are this way in order to be malleable so they can be worked.
Some liquids are denser than others. In general, everyday experience, most liquids are denser than gases, but not as dense as solids. There are some exceptions to this rule.
By making the substance vibrate. The denser the material, the faster the sound travels. Most solids are denser than most liquids, which are denser than most gasses.
Denser than gases but (most often) less dense than solids.
Sound travels the fastest in solids. Solids being the most denser make sound travel fastest as compared to liquids and gases which have speed of sound relatively less than solids.
This depends on the solids, but filtering usually takes most solids out of most liquids.
Since most of the time we are concerned with heat being transferred via conduction, the denser the material, the easier it is to conduct heat. Except for the rare anomaly (think ice vs liquid water) solids are denser than their corresponding liquid forms. All that is a gross simplification of course. Many liquids heat quite a bit better than solids and convection (which can occur in liquids but not solids) can greatly aid in the speed of "heating up", so the generalization that solids heat up faster than liquids is only a tendency rather than a rule.
Sound travels through solids faster than other states of matter because most solids are denser than liquids. Sound waves travel faster through denser media than through less dense media. and the solids have high elasticity.. sound travel faster in elastic bodies
Water has a lower density as a solid than it does as a liquid. In the vast majority of substances are denser as solids than as liquids.
expand
Gases have the greatest volume. Liquids are denser than gases. Most solids are slightly denser than liquids. One important exception is ice. Ice is solid water, but because of its crystal structure, ice is not as dense as liquid water.
Not only liquids but also solids expand as they get hotter, with few exceptions.
Yes, sound can travel through most mediums including solids and liquids. However, it cannot travel through a vacuum.