While looking at bromine (Br) on the periodic table, a student needs to find another element with very similar chemical properties but with a different atomic mass. Which best describes the student’s options?

Elements in the same vertical column, or group, of the periodic table have similar chemical properties because they have the same number of valence electrons. Bromine is in Group 17, so other halogens in that column are good matches, and they have different atomic masses. Therefore, the best choice is “There are many possible elements, and they are all in the same vertical column as bromine.”

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