Define Mendeleev's Periodic Law

Compare and contrast the arrangement of elements in mendeleev's Periodic Table and Modern Periodic Table.

Define Modern Periodic Law

besides gallium, which other elements have since been discovered that were left by Mendeleev in his periodic Table?

How many periods are there in the Modern Periodic Table?

Who developed Modern Periodic law?

What were the criteria used by mendeleev in creating his periodic Table?

Define time period of oscillation.

State the modern periodic law. How many groups and periods are present in modern periodic table?