Question

atomic number of four elements p q r and s are 4,14,17 and 20 respectively which of these element will show similar chemical properties and why

Answer 1

Out of the above mentioned elements...the p( atomic no-4) and s( atomic number -20) with electronic configuration  (2,2) and (2,8,8,2) will show similar chemical properties...this is because the chemical property of the element depends upon..the valence electron...as p and s both have 2 electrons in their valence shell therefore they both will show similar chemical properties...furthermore they belong to same group...in periodic table...