Draw a dot diagram for the molecule \(\mathrm{O}_{3}\), ozone, the molecule in our upper atmosphere that protects us from the Sun's harmful ultraviolet electromagnetic radiation. (Hint: Only the middle oxygen atom forms bonds with the two other oxygen atoms.)

Valence electrons play a pivotal role in chemical bonding, as they are the outermost electrons of an atom and are involved in forming bonds with other atoms. An understanding of valence electrons is crucial when appreciating the structure of molecules, like ozone (O₃).

Each oxygen atom in ozone has 6 valence electrons since oxygen is in Group 16 of the periodic table. When we are drawing a dot diagram for a molecule like ozone, we must account for all the valence electrons of the atoms involved. In ozone's case, there are a total of 18 valence electrons (3 oxygen atoms each with 6 valence electrons).

These electrons must be distributed properly to show the bonding between atoms and the lone pairs of electrons that do not participate in bonding. The structure and stability of the molecule significantly depend on how these electrons are arranged.

Chemical bonding is the force that holds atoms together in molecules. Bonds form between atoms when valence electrons are shared or transferred from one atom to another, creating a full outer shell of electrons, which is stable according to the octet rule. In the ozone molecule, we see two types of chemical bonds: a double bond and a single bond.

The double bond involves sharing of two pairs of electrons between two oxygen atoms, while the single bond involves sharing just one pair of electrons. The middle oxygen atom uniquely participates in both types of bonding with the other two oxygen atoms. These bonds are what give the ozone molecule its bent structure and enable it to absorb ultraviolet radiation.

Lewis structures, also known as Lewis dot diagrams, are simplified representations of molecules showing how valence electrons are distributed around atoms and how they participate in bonding. They are an essential tool for visualizing the arrangement of electrons and the connections between atoms within a molecule.

To draw the Lewis structure for ozone, we start by aligning the atoms and creating bonds as indicated by the exercise. The remaining valence electrons are then placed around the atoms as lone pairs to satisfy the octets. The structural representation gives us a visual summary of the molecules' makeup, indicating how electrons are shared and positioned as lone pairs.

The octet rule is a chemical rule of thumb that states atoms tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. The octet rule guides the distribution of electrons in the Lewis structures of most molecules, including ozone.

When we distribute the 18 valence electrons of ozone, we do so with the aim of completing the octet for each oxygen atom. This is depicted in the dot diagram where once the bonding electrons are placed, remaining electrons are allocated as lone pairs which do not participate in any bonding but are crucial for completing the atoms' octets. The ozone molecule clearly illustrates the octet rule in action, with each oxygen atom fulfilling the rule for maximum stability.