Question

The electron configuration of an atom is $2,8,7$ to which of the following elements would it be chemically similar?

• A. $\text{Nitrogen (Z=7)}$
• B. $\text{Fluorine (Z=9)}$
• C. $\text{Phosphorous (Z=15)}$
• D. $\text{Argon (Z=18)}$

Answer 1

The correct option is B $\text{Fluorine (Z=9)}$

If the configuration of an atom is $2,8,7$ that means valence shell have $7$ electrons,

In Fluorine, the electronic configuration is $2,7$, it also have $7$ elections in valance shell

Hence, they are chemically similar.