Question

All members of Group IA have similar reactivity because:

• A. they have the same number of protons
• B. they have the same number of electrons
• C. they have similar outer shell electron configurations
• D. they have valence electrons with the same quantum numbers
• E. they have the same number of neutrons

Answer 1

The correct option is C they have similar outer shell electron configurations
Option C is the correct answer.

Reactivity of an element depends on the number of electrons present in the outermost shell of an element. All group 1A elements have one electron in their outermost orbits. For example, Lithium, Sodium, Potassium, Rubidium etc all have one electron in their outermost shell. Hence their reactivities are also same.