Chapter 5.6, Problem 4QQ

Interpretation Introduction

Interpretation:

The number of nonbonding electrons that is present in ${\text{CH}}_{\text{4}}$ molecule has to be chosen from the given options.

Concept Introduction:

Lewis structure clearly depicts the bonding and nonbonding electrons in the atom.  This is only partially useful for the molecule that contains one or more multiple bonds and when coordinate covalent bond is present in the molecule.  For drawing Lewis structure a systematic procedure is followed.  They are,

• The total number of valence electrons that is present in molecule is calculated by adding all the valence electrons of the atoms present in the molecule.
• The chemical symbols for the atoms that is present in the molecule is written in the order that they are bonded.  After this a single covalent bond is placed between each atoms as two electrons.
• The nonbonding electrons are added to each atom that is bonded to the central atom so that it contains octet of electrons.  For hydrogen alone the “octet” is only two electrons.
• The remaining electrons has to be placed on the central atom in the structure.
• If there is no octet of electrons present in the central atom, then use one or more pairs of nonbonding electrons that is bonded to the central atom to form double or triple bonds.
• The total number of electrons has to be counted and it has to be confirmed whether the count is same as that of the number of valence electrons that is available for bonding.