Chemistry writing compounds

Binary Ionic Identification

Metal + Nonmetal (2 elements)

Binary Ionic Naming & Formula Rules

• Name cation (metal) first, anion second with -ide

• Balance charges to net zero (reduce subscripts if possible)

Binary Ionic Examples

Mg²⁺ + Br⁻ → MgBr₂ (Magnesium bromide)

Ca²⁺ + O²⁻ → CaO (Calcium oxide)

Ionic w/ Transition Metals Identification

Transition Metal + Nonmetal

Ionic w/ Transition Metals Naming & Formula Rules

Use Roman numerals in parentheses for the metal charge

Ionic w/ Transition Metals Examples

Fe³⁺ + Cl⁻ → FeCl₃ (Iron (III) chloride)

Hg₂O (Mercury (I) oxide)

Ionic w/ Polyatomic Ions Identification

3+ elements (contains a polyatomic ion)

Ionic w/ Polyatomic Ions Naming & Formula Rules

• Treat polyatomic ion as a single unit

• Use parentheses if adding a subscript to the polyatomic ion

• Cations (e.g., NH₄⁺) always go first

Ionic w/ Polyatomic Ions Examples

Ca²⁺ + NO₃⁻ → Ca(NO₃)₂ (Calcium nitrate)

NH₄Cl (Ammonium chloride)

Covalent Compounds Identification

Nonmetal + Nonmetal (sharing electrons)

Covalent Compounds Naming & Formula Rules

• Use Greek prefixes (mono-, di-, tri-, tetra-, penta-, hexa-) for atom counts

• Second element ends in -ide

• Do not use mono- on the first element

Covalent Compounds Examples

CO₂ (Carbon dioxide)

N₂O₄ (Dinitrogen tetroxide)

P₂O₅ (Diphosphorus pentoxide)

Covalent Lewis Structures Identification

Nonmetals sharing valence electron pairs

Covalent Lewis Structures Rules

• Least electronegative in middle (Carbon almost always middle; Hydrogen/Fluorine outside)

• H needs 2 electrons; all others need 8

• Single line = 1 shared pair (2e⁻), double = 2 pairs, triple = 3 pairs

Covalent Lewis Structures Examples

CH₄ (Carbon tetrahydride / Methane)

O₂ (Double bond, O=O)

N₂ (Triple bond, N≡N)

Binary Acids Identification

Starts with H + Nonmetal (no oxygen)

Binary Acids Naming & Formula Rules

hydro- + [root of nonmetal] + -ic acid

Binary Acids Examples

HBr (Hydrobromic acid)

HCl (Hydrochloric acid)

Oxyacids Identification

Starts with H + Polyatomic Ion (has oxygen)

Oxyacids Naming & Formula Rules

• Polyatomic ending in -ite → -ous acid

• Polyatomic ending in -ate → -ic acid

Oxyacids Examples

H₂SO₃ (Sulfite) → Sulfurous acid

H₂SO₄ (Sulfate) → Sulfuric acid

HNO₂ (Nitrite) → Nitrous acid

Greek Prefixes (1-10)

1: Mono- (only 2nd element)

2: Di-

3: Tri-

4: Tetra-

5: Penta-

6: Hexa-

7: Hepta-

8: Octa-

9: Nona-

10: Deca-

Acid Naming Memory Trick

"I rate it icky, I take a Bite and it's delicious" (-ate → -ic, -ite → -ous)