question_answer

Na, Mg and Al are the elements of the same    period of Modern Periodic Table having one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius (ii) is least reactive? Justify your answer stating reason for each case.

Answer:

Na - atomic size decreases from left to right due to increase in the nuclear charge.

Al - The tendency to lose electron decreases left to right.