Na, Mg and AI are the elements of the same period of Modern Periodic Table

Na, Mg and AI are the elements of the same period of Modern Periodic Table having one, two and three valence electrons respectively. Which of these elements

1.has the largest atomic radius.
2. is least reactive? Justify your answer stating reason for each case.

Answer:

  1. Na has the largest atomic size because the atomic size decreases from left to right due to the increase in the nuclear charge.
  2. AI is least reactive because the tendency to lose electrons decreases from left to right.