Question

A,b,c are the elements with atomic numbers 5,7,19 which of the above element has more atomic size

Answer 1

Answer:

19

Explanation:

because it's electronic configuration is 2,8,8,1

Answer 2

C element has the more atomic size.

Given-

• Atomic number of A = 5
• Atomic number of B = 7
• Atomic number of C = 19

Electronic configuration of A = 1s² 2s² 2p¹

Electronic configuration of B = 1s² 2s² 2p³

Electronic configuration of C = 1s² 2s² 2p⁶3s² 3p⁶ 4s¹

From the above electronic configurations we can clearly see that A and B elements are form 2nd period and C element is from 4th period.

We know that in a periodic table atomic size decreases in moving from left to right and increase in moving from top to bottom.

So maximum atomic size is of element C and minimum atomic size is of element B.

Atomic size order will be

C > A > B