Question

Which of the following arrangement of electrons do not represent Bohr’s model of an atom correctly?

• A.
• B.
• C.
• D.

Answer 1

Answer: (B), (D)

According to Bohr's model:

The maximum number of electrons present in a shell is given by the formula 2n${}^2$, where 'n' is the orbit number or energy level index, 1,2,3,….

Hence, the maximum number of electrons in each shell is as follows

First orbit or K-Shell will be=$2$ $\times$ $1^2$=$2$

Second orbit or L- Shell will be=$2$ $\times$ $2^2$ = $8$

Third orbit or M- Shell will be= $2$ $\times$ $3^2$ =$18$

Fourth orbit or N- Shell will be= $2$ $\times$ $4^2$= $32$

and so on..

Option (B) has 4 electrons in the first shell (it can't be more than 2)

And option (D) has 9 electrons in the second shell (it can't be more than 8)

Hence, B and D do not represent Bohr’s model of an atom correctly.