what is the diference between a solid and a fluid? what is the difference between a gas and a liquid?

Answer 1

Lore, Above, has the Most Direct Answer, I personally Like Feynman's Explanation In "Six Easy Pieces".

Answer 2

Following is a very simplified explanation without the scientific jargon: -

Liquids and gases are both fluids, they will flow.
Some very finely separated solids can be classed as fluid because they too, will flow. (As in the catalyst in a Catalytic Cracking Unit in a petroleum refinery)..

Mainly, 'Solids have a strong attraction between molecules and have a definite shape and volume'.

'Liquid molecules are further apart and have lower attractive forces which allows them to move around more. A liquid can change its shape but not its volume'...It will take the shape of the vessel containing it.

'Gases have their molecules much further apart resulting in little or no attraction forces. A Gas therefore can change both shape and volume easily' and will fill the space available to it.

Answer 3

simplest explanation would be
molecules in solids are very close to each other the force of attraction between any two solid molecules is high thats why solids have defenite shape&volume
molecules in liquid are a bit faraway compared to solids the forces of attraction between any two liquid molecules is weaker than solids thus liquids have a defenite volume but no shape
molecules in gases are further apart than liquid the forces of attraction between any 2 gas molecules is weakest compared to solids&liquids thus gases neither have defenite volume nor shape

Answer 4

The difference in how close the molecules are. In solids, the molecules are packed tight together, allowing almost no room fo rmovement. In liquids, the molecules are spaced a little further apart, allowing for some movement. In gases, molecules are very far apart, allowing for a lot of movement.

Answer 5

In a solid the molecules are vibrating in place. It holds its shape and volume.
The term fluid refers to liquid and gas, things that flow.
Liquids has molecules with more energy, they can slide over each other and will take the shape of the container, but will hold their volume.
Gases have more energy in the molecules. They will take the shape and fill any container they are in.

Answer 6

Solids (crystals) have long-distance order, i.e. periodic
lattice. Corelation between probablities to find
atoms at positions x1 p(x1) and x2 p(x2) remains periodic
and non-constant even at infinity. This long-range order
manifests itself in X-ray diffraction as presence of
sharp zero-width A(k_i)δ(k-k_i) peaks of intensity for
ceratian wave vectors k_i. The amplitude A is called
parameter of order, and it is ether non-zero (for solid
crystals), or zero for any liquid or gas.

Liquid and gaseous phases are indistigushable, except
when in equilibrium along phase separation line.
(A couple of exceptions exist with superfluid liquids,
which are strictly speaking are not liquids at all).

Answer 7

Start with a closed thermodynamic system of an ice cube in a glass. As you add energy in the form of heat, the motion of the water molecules increases, but stays in the form of vibration, with the molecules staying in place within the solid structure. That's 20 people holding hands in a circle, swaying or walking faster back and forth, but still holding hands.

It takes energy to break the 'bonds' of a water molecule with its solid structure. But if you add enough energy, these bonds break and the molecule can move more freely. When no one is holding hands, the whole system is liquid.

In terms of thermodynamic calculations, the whole system will be in whatever state (solid, liquid, gas, or a mixture) minimizes the Gibbs Energy of the system.

With carbon forming the regular crystalline structure of diamond, I think it really is a chemical bond, where the bonding between adjacent carbon atoms is the same bond as between the carbon atom and each oxygen atom in carbon dioxide.

In this covalent bond, electrons tend to congregate between adjacent nucleii because they are electrostatically attracted to both. This tends to draw the nucleii together. But electrostatic repulsion between the nucleii pushes them apart, and the whole structure has a lower energy when some outer electrons are orbiting multiple nucleii than when the electrons stay within a single atom.

In its liquid form, the water molecules are held together by various intermolecular forces, mainly the hydrogen bond. If they start to move farther apart, the strength of the force of the hydrogen bond tends to move them back together. If they start moving closer together, the repulsive electrostatic force between the positively-charged nucleii dramatically increases. There are no free valence electrons in the outer shells of the atoms to form new covalent bonds, so there is no other mechanism to draw them closer.