Question

Gradation in Properties:  Valency, Atomic number, Metallic and Non-metallic properties.​

Answer 1

please specify property

are you talking about the modern periodic table

Answer 2

The gradation for the given properties in the modern periodic table is mentioned below:

1.Valency-

In a group, the number of valence electrons is same in case of all the elements and therefore, have the same valency.

In a period, valency increases from the left to right( ranging from 0-8) across the period.

2. Atomic number-

In a group, the atomic number decreases while going down the group.

In a period, the atomic number increases from left to right of a periodic table.

3. Metallic and non metallic properties-

Down the group, the metallic property of the elements increases while non-metallic property decreases.

Across a period, it is just the opposite i.e. the metallic property decreases from left to right and non-metallic property increases.