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	O^2-	Nitride	N^3-
Chloride	Cl ^-	Sulphide	S^2-	Borate	BO₃^3-
Bromide	Br ^-	Sulphate	SO₄^2-	Phosphide	P^3-
Iodide	I ^-	Sulphite	SO₃^2-	Phosphate	PO₄^3-
Hydroxide	OH ^-	Carbonate	CO₃^2-
Cyanide	CN ^-	Oxalate	C₂O₄^2-
Nitrate	NO₃-	Dichromate	Cr₂O₇^2-
Nitrite	NO₂-	Chromate	CrO₄^2-
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
Email Id : [email protected]

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