Nursing Entrance Exam (NEX) Practice Exam

The vertical columns on the periodic chart are known as groups. This term reflects how elements within the same group share similar chemical properties and behaviors due to having the same number of valence electrons. For instance, elements in Group 1 (the alkali metals) all have one valence electron, making them highly reactive with similar reactions across the group. The arrangement of elements into groups helps to predict their reactivity, bonding, and specific properties, making it a fundamental aspect of understanding chemical behavior. This systematic classification allows chemists and students alike to effectively compare elements and understand trends in the periodic table. In contrast, periods refer to the horizontal rows of the periodic table, and ions refer to charged particles formed when atoms lose or gain electrons. Metalloids are a specific category of elements that exhibit properties of both metals and nonmetals, but they do not represent the vertical structure of the periodic table.