Using the periodic table, predict which elements will have similar chemical
properties or reactivity?
A.Nitrogen, sulfur, and bromine
B. Rubidium, yttrium, and zirconium
C.Magnesium, strontium, and barium
D.Cadmium, calcium, and carbon
The Correct Answer and Explanation is:
The correct answer is C. Magnesium, strontium, and barium.
Explanation:
To predict which elements will have similar chemical properties or reactivity, we need to understand the concept of periodicity. Elements in the same group (vertical columns) of the periodic table share similar chemical properties because they have the same number of valence electrons. The number of valence electrons determines how an element will bond with others and its reactivity.
Let’s analyze each choice:
A. Nitrogen, sulfur, and bromine:
These elements are from different groups in the periodic table. Nitrogen is in Group 15, sulfur is in Group 16, and bromine is in Group 17. While they are all nonmetals, their chemical properties differ significantly because they have different numbers of valence electrons (5 for nitrogen, 6 for sulfur, and 7 for bromine). Nitrogen tends to form three covalent bonds, sulfur can form two, and bromine typically forms one bond, indicating differing reactivity. Therefore, they do not exhibit similar chemical properties.
B. Rubidium, yttrium, and zirconium:
These elements are from different groups as well. Rubidium is an alkali metal (Group 1), yttrium is a transition metal (Group 3), and zirconium is also a transition metal (Group 4). Although yttrium and zirconium are both metals, they belong to different groups and have different chemical behaviors. Rubidium, being an alkali metal, is highly reactive with water, while yttrium and zirconium are much less reactive. Thus, these elements do not share similar chemical reactivity.
C. Magnesium, strontium, and barium:
These elements are all in Group 2, known as the alkaline earth metals. They share the same number of valence electrons (two electrons) and therefore have similar chemical properties. For instance, all three react with water, though the reactivity increases as you go down the group (barium reacts more vigorously than magnesium). They also form similar types of compounds, such as oxides and hydroxides, that share comparable chemical properties.
D. Cadmium, calcium, and carbon:
Cadmium is a transition metal (Group 12), calcium is an alkaline earth metal (Group 2), and carbon is a nonmetal (Group 14). These elements belong to different groups, and their chemical properties are significantly different. For example, calcium reacts with water, while carbon does not, and cadmium is more likely to form metallic bonds rather than covalent bonds like carbon. Hence, these elements do not have similar reactivity.
Therefore, Magnesium, strontium, and barium (Option C) are the elements that will have similar chemical properties and reactivity because they are all alkaline earth metals in Group 2 of the periodic table.