Polar and Nonpolar Bonds in Chemistry

Polar and Nonpolar Bonds

• Polar Covalent Bond: Occurs between atoms with differing electronegativities; shared electrons are closer to the more electronegative atom, resulting in partial charges.
• Nonpolar Covalent Bond: Electrons are shared equally between two atoms with similar electronegativities.
• Nonpolar Molecule: Does not exhibit charged ends, resulting from equal sharing of electrons.

Molecular Polarity

• Trigonal Pyramidal & Bent Shapes: These molecular geometries lead to polar molecules (e.g., water, HF), due to unequal bond distribution.
• Tetrahedral & Linear Shapes: Nonpolar if the covalent bonds are identical, as seen in CF4.

Specific Molecular Examples

• CF4 (Carbon Tetrafluoride): Nonpolar due to tetrahedral shape and identical polar covalent bonds despite existing electronegativity differences.
• BF3 vs. NF3: BF3 is nonpolar because its trigonal planar shape allows equal bond distribution, while NF3 is polar due to its trigonal pyramidal shape influenced by a lone pair on nitrogen.

Electron Configuration and Compounds

• Boron in BF3: Has only 6 valence electrons, satisfying fluorine’s octets, resulting in fewer than expected.
• Common Compounds:
  • Fe(OH)3: Iron (III) hydroxide
  • NaBr: Sodium bromide
  • CF4: Carbon tetrafluoride
  • N2O3: Dinitrogen trioxide
  • N2O5: Dinitrogen pentoxide

Ions and Their Names

• Common polyatomic Ions:
  • PO4^3-: Phosphate
  • SO4^2-: Sulfate
  • NH4+: Ammonium
  • NO3-: Nitrate
  • CO3^2-: Carbonate
• Monatomic Ions:
  • F^-: Fluoride
  • Cl^-: Chloride
  • S^2-: Sulfide
  • O^2-: Oxide

Atomic Structure

• Isotope: Identical in protons but differing in neutrons affecting atomic mass.
• Atomic Mass: Average mass of all isotopes of an element.
• Mass Number: Sum of protons and neutrons in an atomic nucleus.
• Atomic Number: Defines the element based on the number of protons.

Radioactive Decay

• Types include:
  • Alpha Particle Emission
  • Beta Particle Emission
  • X-ray Emission
  • Gamma Ray Emission
• Radioactive Decay Process: Involves decay of unstable isotopes into stable variants.

Wavelength and Frequency

• Inversely related: Shorter wavelengths equate to higher frequencies and energies, while longer wavelengths correlate with lower frequencies and energies.

Nuclear Equations

• Format: Shows atomic and mass numbers for involved particles; significant in illustrating decay processes.

Isotopes Identification

• Determine which atoms are isotopes by comparing the number of protons; for example, 14/6A, 14/7B, 15/7C, and 15/8D identify isotopes based on atomic number similarity.