Day: June 21, 2020
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Class 9th – VALENCY OF IONS
Valency of ion is equal to the charge of the ions. Cations carry positive charge whereas Anions carry negative charge. When the valency is 1 for cations, they are called as Monovalent Cations. When the valency is 2 for the cations, they are called as divalent cations. When valency is 3 for the cations, they…
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Class 9th – CHEMICAL FORMULAE
It determines the composition of a molecule of the Compound, with the symbols of the elements present in it. When a metal and a non metal combine it result in the formation of Ionic Compound. The compounds that are formed by Ions. The ions present in KNO3 (Potassium nitrate) are K⁺ & NO3ˉ Rules for…
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Class 9th – ATOMIC MASS OF AN ELEMENT
Atoms of elements are very small. To understand about atomic mass, it is a need to know about Carbon-12. Carbon-12 can be stated as no. of protons= 6 & no. of neutrons= 6 thus making it as 12. Carbon-12 atoms has been made as atomic mass of exactly 12 atomic mass unit. Earlier the unit…
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Class 9th – ATOMS AND MOLECULES
Atoms are indivisible particles which cannot be divided further. The Indian philosopher Kanada was the first to call that matter are made up of small particles called Parmanu. John Dalton called matter is made up of small particles called Atom. LAWS OF CHEMICAL COMBINATION: LAW OF CONSERVATION OF MASS LAW OF CONSTANT PROPORTION LAW OF…