A student attempts to arrange four elements (as shown below) in order from most reactive to least reactive.
Is the arrangement correct, and why (or why not)?
A. Yes. An element’s reactivity decreases along with its atomic number.
B. Yes. An element’s reactivity decreases from left to right on the periodic table.
C. No. An element’s reactivity decreases from right to left on the periodic table.
D. No. An element’s reactivity decreases as atomic mass increases.
The correct answer is B. Yes. An element's reactivity decreases from left to right on the periodic table.
Elements in the same group on the periodic table have similar chemical properties, including reactivity. In this case, the elements are in the same group, so their reactivity decreases as you move from left to right. This is due to the increasing electronegativity of the elements as you move across the periodic table, which decreases their reactivity.
Therefore, the arrangement is correct based on the trend of reactivity on the periodic table.