Question

write the number of periods and groups present in the modern periodic table state the changes in valency and metallic characters of element as well move from left to right a period also state the characters in any in the valency and atomic size of element as well go down the group

Answer 1

18 groups and 8 periods left to right move in a periodic table metallic character decrease also atomic radii decrease and valency increse

Answer 2

there are 18 groups and 7 periods In periodic table