Chapter 25.9, Problem 2Q

Interpretation Introduction

Interpretation: The oxidation number of $Tc$ in the pertechnetate ion, electronic configuration of a $T{c}^{n+}$ ion with a charge equal to the above mentioned oxidation number and its magnetic nature (diamagnetic or paramagnetic) has to be given.

Concept introduction:

The number of electrons an atom tends to give up or gain in a chemical reaction is called oxidation number.

• Rules for assigning oxidation number

1. 1. 1. The oxidation number of the atom of an uncombined element is zero.
   2. 2. The sum of the oxidation numbers of all atoms in a compound must equal to the total charge on the species.
   3. 3. Hydrogen has an oxidation number of +1 unless it is combined with metals, in which case it has an oxidation number of -1.
   4. 4. Oxygen has an oxidation number of -2, except in peroxides where it is -1 and in $O{F}_2$ where it is +2.

Arrangement of electrons in the orbitals of an atom is called electronic configuration. Atom has sub atomic particles like electrons, protons and neutrons. Among which only the number of electrons is considered for electronic configuration.

The atom having unpaired electrons in their orbital is called paramagnetic. When it is having paired electrons is called diamagnetic.