Question

Ions of the elements oxygen (O), sulfur (S), and selenium (Se) usually have charges of -2. Ions of the elements fluorine (F), chlorine (Cl), and bromine (Br) usually have charges of -1.

This demonstrates that

A. elements in different groups all have the same properties.

B. elements in the same group share certain properties, and each group has unique properties.

C. each group of elements has the same properties, but each element within a group has unique properties.

D. elements in the same group do not share any properties.