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

Explanation

The atomic number of calcium is 20, so its electronic configuration is 2,8,8,2. Thuc calcium has 2 valence electrons (in its outermost shell). Now, that element which has 2 valence electrons will have physical and chemical properties resembling that of calcium. we have now to write the electronic configurations of all the elements one by one. The electronic configuration of element having atomic number 12 is 2,8,2. It has 2 valence electrons just like calcium. so, element havving atomic number 12 will have physical and chemical properties resembling that of calcium.