Chemical Formulas and Bonding

Types of Chemical Formulas

• Molecular Formula
  • Lists element symbols and subscripts.
  • Example:
    • N2: Two nitrogen atoms
    • CH4: One carbon and four hydrogen atoms
    • C2H4O2: Two carbon, four hydrogen, and two oxygen atoms
• Structural Formula
  • Includes connectivity information.
  • Important for compounds like acetic acid and methyl formate.

Elements and Compounds

Elements

• Atomic Elements
  • Exist as single atoms (e.g., Helium, Neon)
• Molecular Elements
  • Exist as molecules (e.g., O2, S8, P4)
• Diatomic Elements
  • Elements that naturally occur in diatomic forms: Br2, I2, N2, Cl2, H2, O2, F2

Compounds

• Molecular Compounds
  • Held by covalent bonds (e.g., H2O)
• Ionic Compounds
  • Held by ionic bonds (e.g., NaCl)

Chemical Bonds

Covalent Bonds

• Occur between non-metals
• Involve sharing of electrons
• Compounds exist as discrete molecules (e.g., CO2)

Ionic Bonds

• Occur between a metal and a non-metal
• Involve transfer of electrons
• Positive cation and negative anion attraction
• Example: NaCl forms lattice structures
• Formula Unit: Smallest electrically neutral unit in ionic compounds (e.g., CaCl2)

Polyatomic Ions

• Compounds with covalent bonds but have overall charge
• Form ionic bonds with opposite ions
• Example: Sodium hypochlorite (NaClO)
  • Na+ cation and ClO- anion

Naming Compounds

• Practice is crucial for effective communication of chemical contents
• Worksheets and example videos are available for practice
• Example: Sodium hydrogen carbonate (NaHCO3), also known as sodium bicarbonate

Additional Notes

• Naming conventions are essential for understanding chemical formulas
• Engage with practice materials to develop proficiency in naming and recognizing compounds.