CBSE Science Subject Notes
CBSE Guess > eBooks > Class X > Atoms and Molecules By Mr. Ajay Kumar
Science
Atoms and Molecules
IONS AND THEIR TYPES : -
Ion is a charged chemical particle. Ions are two types.
(i) Cation.
(ii) Anion.
(iii) Polyatomic ion.
CATION : -
An ion carrying positive charge is called cat ion.
ANION : -
An ion carrying negative charge is called anion.
POLYATOMIC ION : -
A group of two or more atoms carrying charge is called polyatomic ion.
MONOVALENT CATIONS VALENCY = +1 DIVALENT CATIONS VALENCY = +2 TRIVALENT CATIONS VALENCY =+3 VALENCY=+4 Hydrogen H+ Magnesium Mg2+ Aluminum Al3+ Carbon C4+ Lithium Li+ Calcium Ca2+ Chromium Cr3+ Sodium Na+ Barium Ba2+ Bismuth Bi3+ Potassium K+ Zinc Zn2+ Antimony Sb3+ Silver Ag+ Copper Cu2+ Ferric Fe3+ Ammonium NH4+ Ferrous Fe2+
MONOVALENTCATIONS VALENCY = 1– DIVALENT CATIONS VALENCY= 2– TRIVALENT CATIONS VALENCY = 3– Fluoride F - Oxide O2- Nitride N3- Chloride Cl - Sulphide S2- Borate BO33- Bromide Br - Sulphate SO42- Phosphide P3- Iodide I - Sulphite SO32- Phosphate PO43- Hydroxide OH - Carbonate CO32- Cyanide CN - Oxalate C2O42- Nitrate NO3- Dichromate Cr2O72- Nitrite NO2- Chromate CrO42- Bicarbonate HCO3- Permanganate MnO4- MOLECULAR MASS : -
The mass of a molecule is called molecular mass.
RELATIVE MOLECULAR MASS : -
The mass of a molecule of a substance compared with one-twelfth mass of a carbon-12 atom is called relative molecular mass.
GRAM MOLECULAR MASS : -
The molecular mass expressed in grams is called gram molecular mass.
FORMULA UNIT MASS : -
The sum of atomic masses of all the atoms in a formula unit of a substance is called formula unit mass.
MOLE CONCEPT : -
The mole provides direct relation between the number of atoms and their mass and the number of molecules and their mass.
MOLE : - *
Mole is a unit which is used to report the amount. This is written as mol. One mole represents a collection of 6.022 X 1023 particles; it is also called Avogadro constant.
MOLAR MASS OF ATOMS : -
The mass of one mole of atoms is called molar mass. Molar mass of atoms is equal to the mass of 6.022 X 1023 atoms.
MOLAR MASS OF MOLECULES : -
The mass of one mole of molecules is called its molar mass. Molar mass of molecules is equal to the mass of 6.022 X 1023 molecules.
MOLE AND ITS ROLE IN CHEMICAL CALCULATIONS : -
. Relation between mass and mole
Number of mole = Given mass of the substance
Molar mass of the substance. Relation between mole and mass
Mass of the substance = Number of mole X Molar mass
. Relation between mass and number of atoms or number of molecules
Number of particles = given mass of the substance
Molar mass of the substance. Relation between mole, number of particles and mass
Mass = Mole X Molar mass = Number of particles X Molar mass
Avogadro number
Submitted By Mr. Ajay Kumar
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