Question

In the Modern periodic table, calcium (atomic number $20$) is surrounded by elements with atomic numbers $12,19,21,38$. Which of these have physical and chemical properties resembling calcium?

• A. $21$ and $38$
• B. $19$ and $21$
• C. $12$ and $19$
• D. $12$ and $38$

Answer 1

The correct option is D $12$ and $38$

The valence shell of $12$ and $38$ contains $2$ electrons in its outermost shell. They lie on the same group. Therefore, they will have physical and chemical properties resembling calcium.