Question

chemistry semester 1 exam on level 25-26
a family of elements that has seven valence electrons is the ______.
○ group 7
○ group 17
○ group 5
○ group 2

Explanation:

In the periodic table, the number of valence electrons for main - group elements is related to their group number. For elements in Group 17 (also known as the halogens), the general electron configuration of their outermost shell gives them 7 valence electrons. Group 7 in the old numbering system is not the correct modern group for elements with 7 valence electrons. Group 5 elements have 5 valence electrons, and Group 2 elements (alkaline earth metals) have 2 valence electrons. So the family of elements with seven valence electrons is Group 17.

Answer:

B. Group 17 (Note: Here we assume the options are labeled as A. Group 7, B. Group 17, C. Group 5, D. Group 2. If the original options have different labels, adjust accordingly. But based on the content, the correct option is the one with "Group 17".)