write the molecular model of solid ,liquid and gas on the basis of motion
Answers
Answer:The physical properties of a substance depends upon its physical state. Water vapor, liquid water and ice all have the same chemical properties, but their physical properties are considerably different. In general covalent bonds determine: molecular shape, bond energies, chemical properties, while intermolecular forces (non-covalent bonds) influence the physical properties of liquids and solids. The kinetic molecular theory of gases gives a reasonably accurate description of the behavior of gases. A similar model can be applied to liquids, but it must take into account the nonzero volumes of particles and the presence of strong intermolecular attractive forces.
alt
Figure 11.1.1
: The three common states of matter. From the left, they are solid, liquid, and gas, represented by an ice sculpture, a drop of water, and the air around clouds, respectively. Images used with permission from Wikipedia.
The state of a substance depends on the balance between the kinetic energy of the individual particles (molecules or atoms) and the intermolecular forces. The kinetic energy keeps the molecules apart and moving around, and is a function of the temperature of the substance. The intermolecular forces are attractive forces that try to draw the particles together (Figure 11.1.2
). A discussed previously, gasses are very sensitive to temperatures and pressure. However, these also affect liquids and solids too. Heating and cooling can change the kinetic energy of the particles in a substance, and so, we can change the physical state of a substance by heating or cooling it. Increasing the pressure on a substance forces the molecules closer together, which increases the strength of intermolecular forces.
Gassim.gif ezgif-1-f994ba668a.gif Solid ezgif-1-33b0ff480e.gif
(a) in the gaseous state (b) as a liquid (c) in solid form
Figure 11.1.2
: Molecular level picture of gases, liquids and solids.
Below is an overview of the general properties of the three different phases of matter.
Properties of Gases
A collection of widely separated molecules
The kinetic energy of the molecules is greater than any attractive forces between the molecules
The lack of any significant attractive force between molecules allows a gas to expand to fill its container
If attractive forces become large enough, then the gases exhibit non-ideal behavior
Properties of Liquids
The intermolecular attractive forces are strong enough to hold molecules close together
Liquids are more dense and less compressible than gasses
Liquids have a definite volume, independent of the size and shape of their container
The attractive forces are not strong enough, however, to keep neighboring molecules in a fixed position and molecules are free to move past or slide over one another
Thus, liquids can be poured and assume the shape of their containers.
Properties of Solids
The intermolecular forces between neighboring molecules are strong enough to keep them locked in position
Solids (like liquids) are not very compressible due to the lack of space between molecules
If the molecules in a solid adopt a highly ordered packing arrangement, the structures are said to be crystalline
Due to the strong intermolecular forces between neighboring molecules, solids are rigid.
Cooling a gas may change the state to a liquid
Cooling a liquid may change the state to a solid
Increasing the pressure on a gas may change the state to a liquid
Increasing the pressure on a liquid may change the state to a solid
Explanation: