Final answer:
The correct list that indicates the order of metallic character is Na > K > Rb, as metallic character increases down a group in the periodic table, making rubidium the most metallic of the three. Option E is correct..
Step-by-step explanation:
The list that correctly indicates the order of metallic character is Na > K > Rb. Metallic character refers to the level of reactivity of a metal, with metals typically being reactive and readily losing electrons in chemical reactions. Within the periodic table, the general trend is that metallic character increases down a group and decreases across a period from left to right.
Therefore, as sodium (Na), potassium (K), and rubidium (Rb) are all in the same group (alkali metals), but Rb is lower than K, and K is lower than Na, the correct order from least to most metallic is Na > K > Rb, which corresponds to option E. This order reflects an increase in reactivity and a decrease in ionization energy as you move down the group in the periodic table. Nonmetals, on the other hand, tend to gain electrons. Based on this information, we can determine the order of metallic character for the elements in the given options.