Chemical Bonding

Remember these?? They can be used to determine how atoms bond with each other. Li N

The Octet Rule Atoms are most stable when their outermost shell is full Level 1 = 2 electrons All other shells = 8 electrons Noble gases have full outer shell so most do not bond with other atoms Other atoms lose, gain, or share electrons to get a full outer shell

Ionic Bond * an electrostatic attraction between a cation and an anion * electrons are lost by the cation and gained by the anion * usually involves a metal and a nonmetal * makes an ionic compound animation

(cations) to get a stable outer shell (revert back to 8) Metals lose electrons (cations) to get a stable outer shell (revert back to 8) Nonmetals gain electrons (anions) to get a stable outer shell (add as many as needed until 8) Ionic bond video

Properties of Ionic compounds Most have high melting points and high boiling points. Many dissolve in water (aqueous solution). Good conductors of electricity (electrolyte) if melted (molten) or dissolved. The greater the degree of ionization or dissociation the greater the conductivity of the solution

Form crystalline structures. Ionic bonds are usually strong and stable. If stressed, the bonds will break along a cleave line.

Covalent Bond * Takes place between two nonmetals * electrons are shared by both nuclei in order for each to attain a full valence shell * a molecule is formed when two or more elements bond covalently * makes a covalent/molecular compound

Properties of Molecular/Covalent compounds Most have low melting points and low boiling points. Many are liquids and gases at room temperature. Nonconductors of electricity. AKA Nonelectrolytes

Which solution contains an ionic compound? How do you know? Which solution below contains molecular/covalent compound? How do you know? C2H5OH Potassium chloride