Chapter 8, Problem 117AP

Interpretation Introduction

Interpretation:

The Lewis structure for the given isoelectronic species is to be drawn and the formal charges on it are to be shown.

Concept introduction:

Lewis dot symbols contain dots, which give information about valence electrons.

In Lewis dot symbol, for each element, dots are mentioned around the symbol of an atom.

In Lewis dot symbol, valence electrons are represented by dots.

Dots are placed above and below as well as to the left and right of symbol.

Number of dots is important in Lewis dot symbol but not the order in which the dots are placed around the symbol.

In writing symbol pairing is not done until absolutely necessary.

For metals, the number of dots represents the number of electrons that are lost when the atom forms a cation.

For second period nonmetals, the number of unpaired dots is the number of bonds the atom can form.

Atomic ions can also be represented by dot symbols, by simply adding (for anions) and subtracting (for cations) the appropriate number of dots from Lewis dot symbol.

Isoelectronic species are those molecules or compounds that have an equal number of electrons.

Due to attraction toward electrons, ions and molecules acquire some charge over themselves, which is called formal charge.

It is given by:

Formal charge = Total number of valence electrons in a free atom – total number of associated electrons.