Chemical Bonding and Nomenclature

ionic bonds

• Formed by electrostatic attraction between oppositely charged atoms.

• Involves transfer of electrons between metals and nonmetals.

covalent bonds

• Formed by the sharing of valence electrons between nonmetals.

• Both elements strongly attract the shared electrons.

metallic bonds

• Not covered in detail but involves delocalized electrons in metals.

ionic compounds

• Composed of metal and nonmetal or metal and nonmetal group.

• Examples: Oxides (e.g., CuO), Salts (e.g., NaCl, FeCl₃).

ions

An atom with a charge due to gain/loss of valence electrons.

monatomic ion

a single atom ion

cation

a positively charged ion (loss of electrons)

• Example: Li → Li⁺ (lithium ion).

• Sometimes includes Roman numeral for transition metals (e.g., Cu²⁺).

anion

a negatively charged ion (gain of electrons)

• Example: Br → Br⁻ (bromide ion).

• A suffix -ide is added (e.g., sulfide S²⁻).

trends in charges

• Cation names often require Roman numerals not listed in periodic tables.

• Relationship between oxidation numbers and charges.

polyatomic ions

• Ions made of multiple atoms with a fixed charge.

• Common examples include:

  • Ammonium: NH₄⁺

  • Acetate: C₂H₃O₂⁻

  • Bicarbonate: HCO₃⁻

  • Carbonate: CO₃²⁻

  • Phosphate: PO₄³⁻

  • Nitrate: NO₃⁻

naming ionic compounds

• Write symbols and determine charges to ensure neutrality.

• Example: Sodium Carbonate → Na₂CO₃.

naming acids

• Consist of covalent bonds but behave like ionic in water.

• Naming based on anion suffix:

  • Hydro- + -ide → -ic acid (e.g., HCl → hydrochloric acid).

  • -ate → -ic acid (e.g., H₂SO₄ → sulfuric acid).

  • -ite → -ous acid (e.g., HClO₂ → chlorous acid).

diatomic molecules

• Seven elements naturally occur as diatomic molecules (H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂).

naming binary molecular compounds

• Comprised of two nonmetals:

  • Use prefixes (e.g., mono-, di-, tri-) to indicate the number of each atom.

  • Example: CO → carbon monoxide, N₂O₅ → dicarbon pentoxide.

practice identification and naming

• Practice with provided compounds to identify and name all types (ionic, acids, etc.).