Question

i] 19K, 3Li, 11Na, 4Be Which of these atoms has smallest atomic radius? Explain it ?

Ii] To which block they belong .​

Answer 1

i) As we know that in a group the upcoming elements or the elements with smaller atomic number have smaller radius. therefore lithium has the smallest radii but in case of periods the atomic radius decreases from left to right this is because the increase in effective nuclear charge which in turn increases the attraction between proton and electron.

Hence Beryllium possess the smallest radii.

ii)

K- 1at group alkali metals

Li -1st group alkali metals

Na-1st group alkali metals

Be -2nd group alkali earth metals

I hope you are clear if not just comment and don't forget to mark my answer as the brainliest.