Question

Which of the following elements will have at least 5 electrons in its L-shell?

• A. Boron
• B. Fluorine
• C. Carbon
• D. Magnesium

Answer 1

Answer: (B), (D)

The correct options are
B Fluorine
D Magnesium

From the given options, only fluorine and magnesium have more than 5 electrons in its L-shell.
Elements with their electronic configuration and enumber of electrons in their L-shell are given below:

$$\begin{array}{ccc}\text{Element}& \text{Electronic configuration}& \text{Electrons in L-shell}\\ \text{Boron}& \text{(2,3)}& 3\\ \text{Carbon}& \text{(2,4)}& 4\\ \text{Fluorine}& \text{2,7}& 7\\ \text{Magnesium}& \text{(2,8,2)}& 8\end{array}$$