Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chemistry Chapter 8 Notes #2 Ionic Bonding/terms Anions and cations are held together by opposite charges. Many ionic compounds are referred to as salts or oxides. Simplest ratio of elements in an ionic compound is called the formula unit. The bond is formed through the transfer of electrons. Electrons are transferred to achieve noble gas configuration. Ionic Bonding Cation + Anion The cation is always written first Formula Units (instead of molecules) The ions come together to neutralize the charge (always have an overall charge of zero) Structure: Positive ions are surrounded by negatives and vice versa Ionic Bonding Na Cl The metal (sodium) tends to lose its one electron from the outer level. The nonmetal (chlorine) needs to gain one more to fill its outer level, and will accept the one electron that sodium is going to lose. Ionic Bonding + Na Cl - Note: Remember that NO DOTS are now shown for the cation! Ionic Bonding Lets do an example by combining calcium and phosphorus: Ca P All the electrons must be accounted for, and each atom will have a noble gas configuration (which is stable). Ionic Bonding Ca P Ionic Bonding 2+ Ca P Ionic Bonding 2+ Ca Ca P Ionic Bonding 2+ Ca P Ca P 3- Ionic Bonding 2+ Ca Ca P 3- Ionic Bonding 2+ Ca P 2+ Ca P 3- Ionic Bonding Ca 2+ Ca P 2+ Ca P 3- Ionic Bonding Ca 2+ Ca P 2+ Ca P 3- Ionic Bonding 2+ Ca 2+ Ca 2+ Ca P P 33- Ionic Bonding = Ca3P2 Formula Unit This is a chemical formula, which shows the kinds and numbers of atoms in the smallest representative particle of the substance. For an ionic compound, the smallest representative particle is called a: Formula Unit Naming Compounds Name Cation first, anion second Monatomic cation – name of element Monatomic anions – drop ending, add –ide Ex. Oxygen = oxide Polyatomic ions = name of polyatomic Transition metals – the oxidation number is written as a roman numeral Examples Sodium Chloride Magnesium Fluoride Potassium Nitride Iron (III) oxide Ammonium Sulfide Lithium Carbonate Strontium Phosphate FeO Fe2O3 Ionic Properties Ionic crystal = crystal lattice High melting points High boiling points Hard, rigid, and brittle 3-dimensional geometric pattern of particles Due to the high strength of the bonds Energy to separate ions (1 mole) = lattice energy