Chapter 3.6, Problem 5QQ

Interpretation Introduction

Interpretation:

Among the given pairs of electron subshells, the one that has the first subshell with more energy has to be chosen.

Concept Introduction:

Electrons are present outside the nucleus of an atom.  These electrons are restricted to some specific regions around the nucleus of an atom.  Electrons do move rapidly in the space about the nucleus is divided into subspaces that are known as shells, subshells and orbitals.

Electron shells are the space region that is present around the nucleus and this contains electrons that possess approximately same energy and which spend most of their time in the same distance from nucleus.  Electron shells are numbered as 1, 2, 3, and so on.  The energy of electron increases as the distance between the nucleus and electron shell increases.  Electron shell can accommodate electrons and it varies because higher the electron shell number, more is the number of electrons that can be present in it.

Electron subshell is the space region in the electron shell which contains the electrons that have same energy.  The number of electron subshell present for each electron shell depends upon the shell number.  Electrons are added to the electron subshell in the electron shell.  The number of electron subshell that is present in an electron shell depends only on the shell number.  If the shell number is 1, then there is only one electron subshell.  If the shell number is 2 means then there is two electron subshells and so on.

Electron orbital is the space region in electron subshell where the electrons with specific energy are most likely to be found.  An electron orbital can hold only two electrons irrespective of the other considerations.  “s” subshell has one orbital, “p” subshell has three orbital, “d” subshell has five orbital and “f” subshell has seven orbitals.

Each and every orbitals have distinct shape.  This does not depend upon the shell number.  “s” orbital is spherical shape, “p” orbital has two lobes, “d” orbitals have four lobes, and “f” orbital has eight lobes.

Electrons that are present within an orbital “move about” in an orbital.  Electron spins on its own either in clockwise or anticlockwise direction.  In an orbital, the two electrons that are present will have opposite spin.  If one electron spins in clockwise direction, the other electron will spin in anticlockwise direction in an orbital.  For two electrons present in the same orbital, this is the most favorable state energetically.