Ionic & Covalent Bonding PDF

Ionic & Covalent Bonding  A compound is a substance made up of two or more di erent elements chemically combined.  The Octet Rule states that when bonding occurs, atoms tend to reach an electronic arrangement with eight electrons in their outermost energy level.  The valency of an element is the...

Ionic & Covalent Bonding  A compound is a substance made up of two or more di erent elements chemically combined.  The Octet Rule states that when bonding occurs, atoms tend to reach an electronic arrangement with eight electrons in their outermost energy level.  The valency of an element is the number of bonds an atom of the element forms when it reacts.  An ion is a charged atom, or group of atoms.  An ionic bond is the electrostatic force of attraction between oppositely charged ions.  Characteristics of Ionic Compounds 1. High melting & boiling points: 2. Solids at room temperature 3. Dissolve in water 4. Conduct electricity:  Covalent bonding involves the sharing of electrons – 1. Most are liquids or gases at room temperature. Those that are solids have low melting & boiling points. 2. They do not conduct electricity when molten or in solution. The reason is because they do not break up to form ions. 3. Most covalent substances do not dissolve readily in water.  Electrons that are shared in a covalent bond are called bond pairs.  Electrons not involved in bonding are called lone pairs.  σ (sigma) bond: is formed by the end-on overlap of orbitals  π (pi) bonds: the sideways overlap of p-orbitals are called  A polar covalent bond is a bond where electrons are unequally shared between 2 atoms.  A non-polar covalent bond exists, when electrons are shared equally between atoms,  Electronegativity is the relative attraction of an atom for the shared pair of electrons in a covalent bond.  Electronegativity values to predict bond type: di = 0 di < 1.7 di > 1.7 non –polar covalent  polar covalent  ionic Anion Tests (Make a table with info in this diagram)