Chemical Bonding

General Chemistry Index

Where are we going with this? This page will give the ability to use laboratory observations and data to compare and contrast ionic, covalent, network, metallic, polar, and non-polar substances with respect to constituent particles, strength of bonds, melting and boiling points, and conductivity; provide examples of each type.

Chemical Bonding
About those compounds… 

Compounds are formed when two or more elements combine chemically in fixed, specific ratios. Combine… What?

Elements combine to form compounds by bonding to other elements—in fixed, specific ratios. They do this in several ways, both intramolecularly (strong) and intermolecularly (weaker).  (See also.)

So what do we mean by bonding? A chemical bond is a force that holds atoms together in a molecule or compound.

Bonds are formed when valence electrons, the electrons in the outermost electron “shell” of an atom, interact.  (See also.) 

It is very important to keep in mind that atoms are most stable when they have eight electrons in their valence shell. This is sometimes called the octet rule.

Compounds form (and bonds are created) driven by this fact.

There are several types of intramolecular bonds.

Ionic bonding occurs when two ions are attracted to each other after one atom has transferred its electron(s) to another. This is usually between a metal and a non-metal. This is an intramolecular bond.

Covalent bonding occurs between two atoms and takes place within the electron orbitals such that full sets of orbitals can be created (octet rule). This usually takes place between two nonmetals that are sharing electrons. This is an intramolecular bond.

Polar covalent bonding occurs when two atoms combine covalently, but when one of them has a higher electronegativity. Polar covalent bonding usually occurs between nonmetals. This is an intramolecular bond.

Intermolecular bonding… 

Hydrogen bonding is an intermolecular attraction which occurs when a hydrogen atom bonded to a strongly electronegative atom exists in the vicinity of another electronegative atom with a lone pair of electrons.

Dipole-dipole interactions are intermolecular attractions that occur when the partially positively charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule.  

London dispersion forces result from intermolecular attraction between compounds resulting from the occasional, random non-uniform distribution of electrons as they move around.

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