Question

Which metal in Period 5 is very reactive and has two valence electrons in each atom? rubidium (Rb) strontium (Sr) zirconium (Zr) silver (Ag)

Answer 1

Answer:

strontium (Sr)

Explanation:

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Answer 2

Answer:

           Strontium (Sr)

Explanation:

                        The condition given in statement is the presence of two valence electron. Hence, first we found the electronic configuration of given atoms as follow;

                       Rubidium                         [Kr] 5s¹

                      Strontium                        [Kr] 5s²

                       Zirconium                         [Kr] 4d² 5s²

                      Silver                                 [Kr] 4d¹⁰ 5s¹

From above configurations it is cleared that only Strontium and Zirconium has two electrons in its valence shell.

We also know that s-block elements are more reactive than transition elements due to less shielding effect in transition elements hence, making it difficult for transition metals to loose electrons as compared to s-block elements. Therefore, we can conclude that Strontium present in s-block with two valence electrons is the correct answer.