To determine which element's behavior is closest to that of potassium (K), we should examine the periodic table and consider the number of valence electrons for each element.
1. Valence Electrons and Periodic Table Groups:
- Elements in the same group/column of the periodic table have the same number of valence electrons. The number of valence electrons largely determines an element's chemical properties.
2. Potassium (K):
- Potassium is in group 1 of the periodic table. All elements in group 1 have one valence electron, leading them to exhibit similar chemical behavior.
3. Comparing the Given Elements:
- Strontium (Sr): This element is in group 2 of the periodic table. Group 2 elements have two valence electrons, which means they do not exhibit the same properties as potassium.
- Chromium (Cr): This element is in group 6 of the periodic table. Group 6 elements have six valence electrons, making their behavior quite different from potassium.
- Krypton (Kr): This element is in group 18 of the periodic table. Group 18 elements are noble gases with eight valence electrons (except helium with two), meaning their chemical properties are very different from those of potassium.
- Francium (Fr): This element is also in group 1 of the periodic table, the same group as potassium. Francium, like potassium, has one valence electron, making its chemical behavior very similar to that of potassium.
4. Conclusion:
- Since francium (Fr) has the same number of valence electrons as potassium (one valence electron), it will exhibit chemical properties most similar to those of potassium.
Thus, the element whose behavior is predicted to be closest to that of potassium is:
D. Francium (Fr)
