Question

The electronic configurations of some elements are given below. Name the elements.

(i) 2, 8, 5 

(ii) 2, 8, 8, 2 

(iii) 2, 8, 1

Answer 1

(i) The electronic configuration is given as 2, 8, 5

The atomic number = total number of electrons 

= 2 + 8 + 5 = 15 

And, the element is Phosphorous with atomic number 15.(ii) The electronic configuration is given as 2, 8, 8, 2. 

The atomic number = 2 + 8+ 8 + 2 = 20. 

And, the element with atomic number 20 is Calcium.(iii) The electronic configuration is given as 2, 8, 1.

Then, atomic number is = 2+8+1 = 11.

And we know that the element is Sodium.