In this post you will learn about valence electrons and valency, isotopes, isobars and fractional atomic masses of certain elements. What are valance electrons? The electrons in the outermost shell of an atom take part in all the chemical reactions given by that element. Thus, these electrons describe the combining capacity or valency of an […]
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In this post we will discuss about Bohr’s model of an atom, Bohr-Bury scheme, how to write electronic configuration of an element and nuclear composition. Rutherford’s nuclear model of atom, although a great contribution to the science, could not explain certain observations. A brilliant description of atomic structure was proposed by Neil Bohr in 1913.
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In this post we will discuss about Rutherford and Thomson Model of an atom. After the discovery of electrons and protons, Sir J.J. Thomson proposed the atomic model. This is described below. What is J J Thomson Model of the atom? In 1898, Sir J J Thomson proposed a model of the atom. This model
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In this post, we will discuss about the anode rays and the discovery of proton and neutron. Anode Rays (Positive Rays or Canal Rays) During his working with cathode rays, Sir J J Thomson had noticed a red glow around the cathode, but on the side opposite the anode. To know the reason for this
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This post includes the topics of Class 9 Chapter 4 Structure of Atom, i.e., Cathode rays and the JJ Thomson model and the discovery of electron. Atoms are too small to be seen even with the most powerful microscope and, too light to be weighed even on the most sensitive balance. In this chapter, we
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In this post, we will discuss about Dalton’s Atomic Theory. Dalton based his theory on two laws: the law of conservation of mass and the law of constant composition. The law of conservation of mass says that matter is not created or destroyed in a closed system. That means if we have a chemical reaction, the amount
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Question: Radhika made a solution by dissolving 40 g of salt in 100 g of water. Her friend, Saloni took 50 g solution from the solution prepared by Radhika and added 5 g more salt to it. Find the final concentration (w/w%) of this new solution. Solution: Mass of solute = 40 g Mass of
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Law of multiple proportions states that if two elements form more than one compound, then the ratios of the masses of the second element which combine with a fixed mass of the first element will always be ratios of small whole numbers. This law is sometimes called Dalton’s Law, named after John Dalton, the chemist who first expressed it. 2.66 g chloride
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In this post we will discuss about mole concept in detail. Have you seen a ₹ 10 note? Probably yes. How about ₹ 100? Probably yes. Most of us have seen the common denominations of Indian currency ranging from ₹ 10 to ₹ 2000. All of these denominations help in the transaction of money. Similarly,
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To know the concept of writing chemical formula of chemical compound, you should know the following: Symbols of the combining elements Valency of the combining elements Name, Representation and Valency of ions Name, representation and valency of some common ions are given below: Note: You have to remember the valencies given in the above table.
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