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.

Na, Mg and Al are the elements of the same period of modern periodic t

1.	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» Solution :(a) NA has the largest atomic RADIUS because it has 11 PROTONS and 11 electrons, therefore least effective nuclear charge. (b) Al is least reactive because it has smallest atomic size due to13protons and13electrons,it has GREATER effective nuclear charge,therefore cannot lose electrons easilyhence it is least reactive.