Question

Why is atomic number considered to be a more appropriate parameter than atomic mass for the classification of elements in a periodic table? How does the metallic character of elements vary as we move (i) from left to right in a period, and (ii) top to bottom in a group in the modern periodic table? Give reasons to justify your answers.

Answer 1

because in between 2 elements it cannot say how many elements can occur due to atomic mass but atomic number increases by one unit from one element to next
metallic charcter decrases in period and increase in period

Answer 2

because atomic number is only varies for one element but there would be different elements have atomic mass close to the other element or we have to put them in between the elements for which there is no space in the periodic table . so atomic no. is more appropriate than atomic mass.

1) metallic properties decreases from going left to right.
2) metallic properties increases from going
up to down.