Question

write the number of periods and groups present in the modern periodic table. 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 go down in a group​

Answer 1

On moving from left to right in a period, the number of valence electrons increases from 1 to 8. On moving from left to right in a period, the atomic size decreases; the size of the atoms decreases. The metallic character of elements decreases on moving from left to right in a period.