PERIODIC CLASSIFICATION OF ELEMENTS

MODERN PERIODIC TABLE:

Ø The modern periodic table is a tabular arrangement of elements in rows and columns, highlighting the regular repetition of properties of the elements.

Features of Periods:

Ø The horizontal rows are called periods. There are seven periods in the periodic table. ‹ First period (Atomic number 1 and 2): This is the shortest period. It contains only two elements (Hydrogen and Helium).

Ø Second period (Atomic number 3 to 10): This is a short period. It contains eight elements (Lithium to Neon).

Ø Third period (Atomic number 11 to 18): This is also a short period. It contains eight elements (Sodium to Argon).

Ø Fourth period (Atomic number 19 to 36): This is a long period. It contains eighteen elements (Potassium to Krypton). This includes 8 normal elements and 10 transition elements.

Ø Fifth period (Atomic number 37 to 54): This is also a long period. It contains 18 elements (Rubidium to Xenon). This includes 8 normal elements and 10 transition elements.

Ø Sixth period (Atomic number 55 to 86): This is the longest period. It contains 32 elements (Caesium to Radon). This includes 8 normal elements, 10 transition elements and 14 inner transition elements (Lanthanides).

Ø Seventh period (Atomic number 87 to 118): Like the sixth period, this period also accommodates 32 elements. Recently 4 elements have been included by IUPAC.

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Electronegativity:

Ø Electronegativity of an element is the measure of the tendency of its atom to attract the shared pair of electrons towards itself in a covalent bond.

Types of ores:

ALLOYS:

Ø An alloy is a homogeneous mixture of two or more metals or of one or more metals with certain non-metallic elements.

Types of Alloys -

1. Copper Alloys (Non- ferrous)

2. Aluminium Alloys (Non- ferrous)

3. Iron Alloys(Ferrous)

MIND MAP