Chemical Bonding and Molecular Structure Test - 1

Gilbert N. Lewis is widely known for his use of simple symbolic representations of elements that show valence electrons as dots.
The Lewis electron-dot symbols focus on the electrons in the highest principal energy level in the atom, the valence electrons.
After all, these are the electrons that participate in chemical reactions. Lewis electron-dot symbols work well for the representative elements.

Lattice energy is an estimate of the bond strength in ionic compounds. It is defined as the heat of formation for ions of opposite charge in the gas phase to combine into an ionic solid.
The stability of ionic bond is directly propotional to lattice energy.

Two chlorine atoms will each share one electron to get a full outer shell and form a stable Cl2 molecule.
By sharing the two electrons where the shells touch each chlorine atom can count 8 electrons in its outer shell. These full outer shells with their shared electrons are now stable and the Cl2 molecule will not react further with other chlorine atoms. One pair of shared electrons form a single covalent bond.

The six noble gases (Helium Neon Argon Krypton Xenon Radon) are found in group 18 of the periodic table. These elements were considered to be inert gases until the 1960's, because their oxidation number of 0 prevents the noble gases from forming compounds readily. All noble gases have the maximum number of electrons possible in their outer shell (2 for Helium, 8 for all others), making them stable.