Notes On Gaseous State This page provides you all details about the gaseous state of BSc standard. Concerned problems will be solved at the end of each concept. Continue till the end to find the easiest explanation of every concept you need in this regard . Postulates of Kinetic Theory of Gases: 1. All gas consist of a very large number of minute particles, called molecules. 2. The gas molecules are extremely small in size and are separated by large distance. The actual volume of the gas molecules is thus negligible as compared to the total volume occupied by the gas. 3. The pressure exerted by the gas is due to the bombardment of the molecules on the walls of the vessel. 4. The gas molecules collide with one another and also with the walls of the vessels. These collisions are perfectly elastic and there is no loss of energy during these collisions. 5. The distance between the gas molecules are very large. Thus, there is no effective force of attraction or r
Notes on Periodic Classification of Elements Disadvantages of Mendeleev’s Periodic Table: 1. Position of hydrogen: It has been confirmed that hydrogen has many characters which match with halogen elements too. But it is only placed in Group IA. Thus position of hydrogen is not clear. 2. Position of isotopes: Since in Mendeleev’s periodic table elements have been arranged according to their atomic masses, isotopes (more than one element) are placed at a one place which is confusing. 3. Position of the isobar: Since in Mendeleev’s periodic table elements have been arranged according to their atomic masses, different elements having different atomic numbers but same mass number (isobars) are placed at one place which is again confusing. 4. No attempts were made to separate metals from non-metals. 5. Dissimilar elements placed together in the same group: Elements showing different chemical properties have been placed together