Question

Fill in the blanks based on features of Mendeleev's periodic table:

The properties of elements gradually change from -------- to -------- on moving from left to right.

Answer 1

Mendeleev periodic table :

1. In Mendeleev, periodic table elements were arranged based on increasing atomic mass. During Mendeleev, only 63 elements were known so after studying the properties of elements he arranged them into vertical columns called groups and horizontal rows are called periods.
2. The metallic character of an element is defined as how easily it can lose its electrons.
3. The metallic character of an element decreases while moving from left to right across a period because while moving from left to right in a period, the number of electrons and protons in an atom increases so this causes an increase in nuclear force by the nucleus on the electrons and hence losing electrons becomes difficult that's why if we move from left to right then the metallic character decreases and non-metallic character of an element increases.

Hence, the properties of elements gradually change from metallic to non-metallic on moving from left to right.