Question

From the elements of the following atomic numbers $9,12,16,20,38,47$ and $56$, identify the elements that belong to same group in periodic table:

• A. $9,16,39$
• B. $12,20,47$
• C. $20,38,47$
• D. $12,20,56$

Answer 1

Answer: (D)

$12,20,56$

Option D is the correct answer as this option has the atomic numbers 12, 20 and 56, which represent the elements Mg, Ca and Ba respectively, which belong to II A group elements. Hence, option D is a set of atomic numbers representing a group.