Answer :
elements in the same group have the same valence electrons. So it is either A or C. elements in the same group don't have identical chemical properties because the valence electrons are in different energy levels. So it should be A. same number of valence electrons and similar chemical properties.
Answer: Option (1) is the correct answer.
Explanation:
As each element of group 17 has 7 valence electrons. Therefore, they tend to show same type of reactivity.
And, when they react with another element then they tend to show a change in their chemical composition.
As a result, we can say that elements of group 17 show similar chemical properties due to the presence of same number of valence electrons.
Thus, we can conclude that as the atoms of the Group 17 elements in the ground state are considered from top to bottom, each successive element has the same number of valence electrons and similar chemical properties.
