When cooled gases change to liquids (usually) and then solids Solids don't change to gases upon cooling
They contract.
Solids do not mix well because there shape can not change. But a liquid and a gas can change their form. For example- you can't just change the shape of ice, but you can change the shape of water. Hope that helps
Solids, liquids and gases expand when heated, liquids and gases expand much more that solids. Gases can be compressed
Solids have tightly packed atoms so there is no space for the atoms to mingle. But in liquids/ gases, the atoms are more spread out and more free to move hence allowing the atoms to mingle.
You mean like mercury and frozen carbon dioxide? In most cases you're correct, but that's because -in general- liquids are closer to being gases than are solids.
Gases tend to float away by themselves. You can pour Liquids BUT, Solids are hard to deform.
expand
That's because of greater intermolecular spaces in gases than in solids
yes
Noble gases are all gases and not solids. In addition they are generally chemically inert as they have completely filled orbitals. Also the most active solids are generally found in group 1
Its down to the molecules in the substance, in gases they are not that close to each other so they can move around quicker and faster so hence diffuse quicker in solids or most they are that tight they can not move are as easily.
Gases the most, then liquids. Solids generally don't diffuse.
I think because mostly it is solids that are all around you, and what you notice the most. So you don't really pay attension to liquids or gases unless your handling them.
Not necessarily. Most if not all of the elements have multiple isotopes, so some are gasses but most are solids.
Metals, like most solids will contract when cooled. When cooled the atoms or molecules slow down, vibrating less often, causing a smaller average separation between them.
Solids do not mix well because there shape can not change. But a liquid and a gas can change their form. For example- you can't just change the shape of ice, but you can change the shape of water. Hope that helps
Solids, liquids and gases expand when heated, liquids and gases expand much more that solids. Gases can be compressed
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.