Chapter 3, Problem 31E

Interpretation Introduction

Interpretation:

The electronic configurations of the given elements are to be drawn and the valence electrons are to be indicated.

Concept Introduction:

 As per Bohr’s model of an atom, electrons are arranged in orbits. Orbits are circular paths in which electrons revolve around the nucleus. There can be a maximum of two electrons in the first orbit; eight electrons in the second orbit and third orbits while eighteen in the fourth orbit.

 The arrangement of electrons in orbits is termed as the electronic configuration. Atoms in which the orbits are completely filled are the least chemically reactive while those in which orbits are incomplete are reactive.

 The electrons present in the outermost orbit in the electronic configuration are called valence electrons. The outermost orbit is termed as valence orbit.