The three states of matter : • solid - ice • liquid - water. • gas - water vapour.
(a) By changing pressure. (b) By changing temperature.
By adding pressure and reducing the temperature, gases can be liquified The gaseous particles come together and begin to attract one another upon applying pressure.
Sublimation is the process by which a substance changes from solid state directly to vapour state. Example : dry ice, naphthalene balls etc.
Latent heat of fusion, also known as enthalpy of fusion, is the amount of energy that must be supplied to a solid substance (typically in the form of heat) in order to trigger a change in its physical state and convert it into a liquid (when the pressure of the environment is kept constant).
Similarly, the latent heat of vaporization or evaporation[tex](L_{v})[/tex] is the heat that has to be given to a unit mass of material to convert it from the liquid to the vapor phase without a change in temperature.
Steam will produce more severe burns than boiling water because steam has more heat energy than water due to its latent heat of vaporisation.
By increasing the pressure, boiling point of the a liquid can be raised without adding soluble impurities.
Early Indian philosophers classified matter in the form of five basic elements – the “Panch Tatva”– air, earth, fire, sky and water.
The cold air that rushes in brings down the temperature of the hot region. Due to this sudden change in temperature, the moisture that rises above the hot region condenses rapidly and falls down as rain.
When a drop of dettol is dropped into water, diffusion occurs as the dettol particles mix with the water particles due to the continuous movement of particles. When a drop of dettol is applied to water, it disperses uniformly. Since there is enough space between the particles of matter in water, this is possible.
Below 63 K, nitrogen freezes and becomes a solid. Above 77.2 K, nitrogen boils and becomes a gas.
The particles move very fast and collide into one another, causing them to diffuse, or spread out, until they are evenly distributed throughout the volume of the container. so gases have highest kinetic energy among other states of matter so they diffuse faster and mixes with other gases.
The smallest group of symmetrically aligned atoms which can be repeated in an array to make up the entire crystal is called a unit cell.
Surface tension decreases with an increase in temperature.
Surface tension is caused by attraction between liquid molecules. Different compounds have different levels of attraction. Water and Ethanol are held together by hydrogen bonds, the strongest of all intermolecular forces.
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1- particles
2- maximum, less than solid, minimum
3- deposition
4-
5- melting point
6- states
7- particles of gases move at high speed
8- surface
9-
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