Chapter 4, Problem 4.139QP

Interpretation Introduction

Interpretation: The ion that efficiently replaces the ${\text{Zn}}^{\text{2+}}$ in the metalloenzyme should be determined.

Concept Introduction:

Atomic Number: Atomic number of the element is equal to the number of protons present in the nucleus of the element which is denoted by symbol Z. The superscript presents on the left side of the symbol of the element.

Periodic Table: The available chemical elements are arranged considering their atomic number, the electronic configuration and their properties. The elements placed on the left of the table are metals and non-metals are placed on right side of the table.

In periodic table the horizontal rows are called periods and the vertical column are called group. There are seven periods and 18 groups present in the table and some of those groups are given specific name as follows,

$\begin{array}{l}\text{Group-1}\to \text{Alkali metal}\\ \text{Group-2}\to \text{Alkaline metals}\\ \text{Group-16}\to \text{Chalcogens}\\ \text{Group-17}\to \text{Halogens}\\ \text{Group-18}\to \text{Noble gases}\end{array}$

Mass number: It is given by the total number of protons and the neutrons present in the nucleus of the element and it is denoted by symbol A. The subscript that lies on the left side of the symbol of the element represents the mass number.

First ionization energy:

The ionization energy is the minimum energy required to remove the electron from an isolated atom which is in the gaseous state results to give gaseous ion with one positive charge.

${\text{atom}}_{\left(\text{g}\right)}\to {\text{ion with positive charge}}_{\left(\text{g}\right)}\text{ + electron}$

Second ionization:

Repeating the same process that is removal of another electron that is second electron from the resulting ion of first ionization is called second ionization.

Third ionization energy:

Removal of electron from ion that results from the second ionization is called third ionization which results to give ion with three positive charges which shows, three electrons gets removed from the atom and the energy associated with it is called third ionization energy.

Cation: Removal of electron from the atom results to form positively charged ion called cation.

Anion: Addition of electron to atom results to form negatively charged ion called anion.

The net charge present in the element denotes the presence or absence of electrons in the element.

In periodic table the horizontal rows are called periods and the vertical column are called group.

Effective Nuclear Charge: It is the positive charge experienced by the valence electrons present in the element due to the screening of innermost electrons present near to the nucleus.

Electronic configuration: It is used to denote the distribution of electrons placed over orbitals that present in the atom.

The rules followed by the electrons are as follows,

The electrons gets distributed starting from lower energy orbital to higher energy orbital, pairing of electrons starts after all the orbitals are singly filled and finally, no two electrons that have same spin can occupy the same orbital.