Author: misamaliraza94
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Electrons
Electrons are the negatively charged sub-atomic particles of an atom. The mass of an electron is considered to be negligible, and its charge is -1. The symbol for an electron is e– Electrons are extremely small. They are found outside the nucleus. Thomson’s model of an atom According to Thomson,(i) An atom consists of a positively…
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Introduction to Structure of an Atom
Atoms Atoms are the building blocks of matter. It is the smallest unit of matter that is composed of three sub-atomic particles: the proton, the neutron and the electron. Cathode ray experiment J. J. Thomson discovered the existence of electrons. He did this using a cathode ray tube, which is a vacuum-sealed tube with a cathode and anode on…
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Structure Of The Atom
Essentially, the structure of an atom comprises protons, neutrons and electrons. These basic components provide the mass and charge of the atoms. The nucleus comprises proton and neutron, with the electron orbiting around that.
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Writing Chemical Formulae
Compounds When two or more elements chemically combine in a fixed ratio by mass, the obtained product is known as a compound. Compounds are substances consisting of two or more different types of elements in a fixed ratio of its atoms. Ions An ion is defined as an atom or molecule which has gained or…
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Atomic Valency
Molecules and Atomicity A molecule is defined as the smallest unit of a compound that contains the chemical properties of the compound. The atomicity of an element is the number of atoms in one molecule of the element. For e.g:- Hydrogen, nitrogen, oxygen, chlorine, iodine, bromine all have two atoms in each of their molecules. So, the…
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Mole Concept
Mole concept & Avogadro Number In a substance, the amount of entities present for e.g. atoms, molecules, ions, is defined as a mole. A mole of any substance is 6.022×1023 molecules. Mole concept is one of the most convenient ways of expressing the amount of reactants and product in the reaction. The value of Avogadro’s number…
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Molecule
The smallest identifiable unit into which a pure substance may be divided while retaining its composition and chemical properties is a molecule, which is a collection of two or more atoms. Molecules of elements A molecule is a collection of two or more chemically bound atoms, whether they are from the same element or another.…
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Molecular mass
Molecular mass of an element is defined as the sum of the masses of the elements present in the molecule. Molecular mass is obtained by multiplying the atomic mass of an element with the number of atoms in the molecule and then adding the masses of all the elements in the molecule.
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Atomic Mass
Atomic mass and atomic mass unit Atomic mass is the total of the masses of the electrons, neutrons, and protons in an atom, or in a group of atoms, the average mass. Mass of an atomic particle is called the atomic mass. This is commonly expressed as per the international agreement in terms of a…
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Dalton`s Atomic Theory
According to Dalton’s atomic theory, atoms, which are indestructible and indivisible building blocks, make up all substances. Unlike other elements, which have atoms of different sizes and weights, an element’s atoms have all the same size and mass. Dalton proposed that the concept of atoms could be used to explain the laws of conservation of…