Question

In the modern periodic table, the element Calcium( atomic number=20) is surrounded by elements with atomic numbers 12, 19, 21, and 38. Which of these elements has physical and chemical properties resembling those of Calcium and why?

Answer 1

The electronic configuration of elements:

Atomic number 12: 2, 8, 2

Atomic number 19: 2, 8, 8, 1

Atomic number 21: 2, 8, 8, 3

Atomic number 38: 2, 8, 8, 18, 2

Element with atomic number 12 will have similar physical and chemical properties as element with atomic numbers 20 and 38.

Hope it helps!!

Answer 2

Explanation:

The element with atomic number 12 has same chemical properties as that of calcium. This is because both of them have same number of valence electrons (2).