Question

explain structure of modern periodic table and it's characteristics.​

Answer 1

Answer:

The modern or long form of the periodic table is based on the modern periodic law. Modern Periodic Law states that the properties of elements are periodic functions of their atomic numbers. The table is the arrangement of elements in increasing order of their atomic numbers. It consists of 18 vertical columns and 7 horizontal rows.

Groups in the Modern Periodic Table

• These groups are numbered from 1 to 18.
• Each group consists of elements having the same outer shell electronic configuration.

Periods in the Modern Periodic Table

• These are numbered as 1, 2, 3, 4, 5, 6 and 7 from top to bottom.
• The 1st period consists of only two elements – Hydrogen and Helium.
• While the 2nd and 3rd period consists of 8 elements each.
• The 4th and 5th period consists of 18 elements each
• Also, the long form of the periodic table consists of a separate panel at the bottom. It consists of 14 elements of the 6th period called the lanthanoids. And 14 elements in the 7th period called the actinoids.
• Each period represents the number of shells or energy levels present in an atom of an element.