State the modern periodic law.

State modern periodic law and assign IUPAC name of element with atomic number 111.

a] Why are sodium and chlorine placed in the same period in the Modern Periodic Table? b] Why do elements placed in the same group of the periodic table have similar chemical properties? c] Who proposed the modern periodic law? On which fundamental property of an atom is it based?

Write the number of periods the modern periodic table has. State the changes in valency and metallic character of elements as we move from left to right in a period. Also state the changes, if any, in the valency and atomic size of elements as we move down a group.

Which is the most electronegative element and the most electropositive element in the modern periodic table ?

Write the number of vertical columns in the modern periodic table. What are these columns called ?

Write the number of horizontal rows in the modern periodic table. What are these rows called ?