The document discusses the key features of the modern periodic table of elements. It is arranged with elements in increasing atomic number organized into 7 periods and 18 groups. Elements are placed into periods based on the number of electron shells in their atoms, with the first period containing hydrogen and helium, and subsequent periods containing additional elements in order of atomic number up to the incomplete seventh period.

1. PERIODIC TABLE
BY GROUP 2

2. WHAT IS A PERIODIC TABLE
The periodic table, also known as the
periodic table of elements, arranges the
chemical elements such as hydrogen, silicon,
iron, and uranium according to their
recurring properties.

3. WHAT ARE THE IMPORTANT FEATURES
OF MODREN PERIODIC TABLE?
The main features of modern periodic table are:-
 Elements are arranged in the increasing order of atomic
numbers.
 The periodic table consist of vertical columns called
groups
 The periodic table consist of horizontal rows called
periods.
 Elements in the modern periodic table are arranged in 7
periods and 18 groups.
 Elements are placed in periods based on the number of
shells in their atoms

4.  Elements are placed in periods based on the number of shells in their
atoms.
 The shortest period is the first period which contains only two
elements – Hydrogen and Helium.
 The second period contains elements from Lithium to Neon.
 The third period contains elements from Sodium to Argon.
 The fourth period contains elements from potassium to krypton.
 The fifth period contains elements from Rubidium to Xenon.
 Sixth period is considered as the longest periods in the periodic table.
It contains elements from Cesium to Radon
 Seventh period is incomplete period.
 At the bottom of the periodic table is a two row block of elements that
contain the lanthanoids and actinides. These groups are classified as
inner transitional metals.

5. PERIODIC TABLE