Question

Write the names given to the vertical columns and horizontal rows in the Modern Periodic Table. How does the metallic character of elements vary on moving down a vertical column ? How does the size of atomic radius vary on moving left to right in a horizontal row ? Give reason in support of your answer in the above two cases.

Answer 1

In the modern periodic table, there are 18 vertical columns known as Groups and 7 horizontal rows known as Periods. 

Metallic character increases on moving down a group in the Modern Periodic table. As we move down the Soup, the electrostatic attraction between the nucleus and the outermost electron decreases due to an increase in the distance between them. This happens because; on moving down the group a new shell an added. So, the valence electron can be easily lost by the element, thereby metallic character increases on moving down a group. 

The size of atomic radius decreases on moving left of right in a horizontal row. When, we move across a period, the number of electrons in the same shell increases. This leads to the greater electrostatic attraction between the nucleus and the outermost electron. This increased attraction pulls the outermost electron closer to the nucleus, thereby decreasing the atomic size.