Chapter 6, Problem 1STP

Interpretation Introduction

Interpretation:

The property from the options that is possessed by elements of the same group of the periodic table needs to be identified.

Concept introduction:

Groups of periodic table are the vertical columns in the table. There are 18 groups present in the periodic table. Some of the groups are, Group I (Alkali metals), Group (II) Alkaline earth metals etc.

Answer to Problem 1STP

1. Number of valence electrons.

Explanation of Solution

Reason for correct options: Elements of every group have equal number of valence electrons in the outer most shell. For example, the elements of group I, such as, Hydrogen, Lithium, Sodium etc. all have one valence electron in their outermost shell. Therefore, the elements of same group possess equal number of valence electrons.

Conclusion

Reason for incorrect options: The physical properties such as boiling point and melting point vary within a group due to their atomic size. So, B is not correct.

The number of electrons of an element depends on its place in the periodic table. Elements may have the similar number of valence electrons but number of electrons of every element in a group is different. So, C is incorrect.

As the number of electrons of every element in a group differs, their electronic configuration is also different. So, C is correct.