question_answer 89)

    Which of the following elements would lose an electron easily? (a) Mg                                   (b) Na                                   (c) K                                       (d) Ca

Answer:

                  (c) Electronic configuration of Mg (atomic number 12) 2, 8, 2. Electronic configuration of Na (atomic number 11) 2, 8, 1. Electronic configuration of K (atomic number 19) 2, 8, 8, 1. Electronic configuration of Ca (atomic number 20) 2, 8, 8, 2. From the above electronic configurations, it is clear that K and Na will lose electron easily to achieve stable configuration. But out of K and Na, K will lose electron more easily because the force of attraction on valence electron of K is least among the given. In other words, larger the atomic radius of an element more easily it can lose its valence electron. Among all these, K has the largest atomic radius, therefore it can lose its valence electron more easily.