Phase Change

Phase Change from Gas to Solid is known as deposition. This Phase Change Gas to Solid is direct conversion of a gas to solid without going to the intermediate state of liquid. During this process heat energy is released from gas to convert into solid. The heat energy released must be equal to ht of condensation and ht of freezing. As ht is released the process is exothermic.
Example of deposition: conversion of water vapor directly into ice in sub-freezing conditions. Formation of snow occurs due to deposition.  Formation of frost on grounds or leafs in sub freezing surroundings is also an example of deposition. Understanding Energy Equation Wavelength is always challenging for me but thanks to all math help websites to help me out.

Opposite process of deposition is sublimation which is Phase Change from Solid to Gas directly without going into liquid state. Sublimation requires absorption of heat by the material and hence it is an endothermic process. At normal pressures, materials have three states at different temperature. But at high pressures, materials sublime at a particular temperature. The ht energy required to be absorbed by the material for this conversion is sum of ht of fusion and ht of vaporization.
For example: Water Sublimation or ice sublimation occurs at temperature less than melting point and pressure which is below its triple point. In Antarctica where temperatures are too low ice sublimes into gas directly. Process of sublimation is also used in purification process where the pure volatile material sublimes and then condenses but the impurities are left behind which are non volatile.
let us see how during a Phase Change Water behaves.  A phse change is not just a matter of temperature but also of pressure. Let see how pressure and temperature effects states of water: Is this topic De Broglie Wavelength Formula hard for you? Watch out for my coming posts.

As shown in Phase Change Diagram Water is found in three states i.e. solid, liquid and gas namely ice, water and steam. When pressure is 1atm, we can observe that water starts converting into ice at 0oC(freezing point). At this point both ice and water exist.  At the same pressure of 1atm water converts into steam at 100oC(boiling point). At this point both steam and water exists. The process of conversion of water into ice is known as freezing and the process of conversion of ice into liquid is melting. When steam converts into water, the process is said to be condensation and when water converts into steam, it is known as boiling. At 374oC and 218atm only steam exists.

At low pressure, ice converts directly into ice through sublimation and steam converts into solid (deposition). Water exists in all phses at triple point (0.01oC, 0.00603atm).