Question

There are three elements $E,F,G$ with atomic numbers $19,8$ and $17$ respectively.
Classify the elements as metals and non-metals.

Answer 1

$E$ has the atomic number 19 with the electronic configuration 2,8,8,1. It has 1 valence electron so it is easy to donate this electron. Hence, $E$ is a metal. $F$ has the atomic number 8 with the electronic configuration 2,6. It has 6 valence electrons and hence it is easy to gain 2 electrons to become stable. So $F$ is a non metal. $G$ has the atomic number 17 with the electronic configuration 2,8,1. It has 7 valence electrons and hence it is easy to gain an electron to become stable. So $G$ is a non metal.