Chapter 6.3, Problem 24SSC

Interpretation Introduction

Interpretation:

The graph of atomic radii v/s atomic number of representative elements of period 2, 3 and 4 needs to be plotted. Also, the periodic trend in atomic radii needs to be explained.

Concept introduction:

Periodic table is a tabular representation of all known elements according to their atomic number. It consists of 18 vertical columns (groups) and 7 horizontal rows (period). There are two series of 14 elements at the bottom of periodic table which are called as inner transition elements.

Answer to Problem 24SSC

Explanation of Solution

The atomic radii of elements depend on the atomic number and number of valence shell in the atom. Across the period the atomic radii decreases due to increase the nuclear attraction whereas the number of valence shell remains same. On the contrary, the atomic radius increases down in the group due to increase in the number of valence shell. Therefore, the graph of atomic radii with atomic number show a decrease in the atomic radii from left to right across the period whereas it increases from 2^nd to 4^th period in the vertical direction.

Conclusion

Across the period, the atomic radii decreases.