Question

if two elements x and y are present on the left and right side of the same group in the periodic table then the atomic size of would be more than that of iron in the given statement and justify your answer ​

Answer 1

PLEASE NOTE - The correct question is :

If two elements X and Y are present on left and right side of the same period in periodic table, then atomic size of X would be more than that of Y. Justify.

The atomic size of X is more than that of Y because X experiences much lesser nuclear pull on its valence electrons as compared to Y.

• The nuclear pull on the valence electrons of an element increases on moving from left to right across a period.

• This is because the atomic number increases as we move towards the right in a periodic table. Therefore, the number of protons in the nucleus also increases which exerts a greater nuclear pull on the valence electrons.

• The number of valence electrons also increases, but they are added in the same shell, since the number of shells across a period remains the same.

• Therefore, the nuclear distance remains the same but the nuclear pull on the outermost electrons increases. This is why the size of the atom shrinks and the element on the extreme right of a period has the smallest atomic size.

• Hence, the element X has a greater atomic size than the element Y.