Chemistry Basics: Atomic Structure and Bonds

Atomic Number

• The atomic number represents the number of protons in an atom's nucleus.

Basic Structure of Atoms

• Hydrogen: Consists of 1 proton and 1 electron.
• Oxygen: Contains 8 protons, 8 neutrons, and 8 electrons.

Mass Number (Atomic Mass)

• The mass number is calculated by adding the number of protons and neutrons in the atom's nucleus.

Subatomic Particles

• Protons: Positively charged particles located in the nucleus.
• Neutrons: Neutral particles also found in the nucleus.
• Electrons: Negatively charged particles orbiting the nucleus.

Atomic Orbitals

• The Pauli Exclusion Principle:
  • A maximum of two electrons can occupy a single atomic orbital.
  • These two electrons must have opposite spins.

Filling of Atomic Orbitals

• The table shows electronic configurations for elements from Lithium (Li) to Neon (Ne).
• Up and down arrows represent electrons with opposite spins.

Types of Chemical Bonds

• Ionic Bond:
  • Formed by electrostatic attraction between ions.
  • An atom losing electrons becomes a positively charged ion (cation).
  • Gaining electrons leads to a negatively charged ion (anion).
  • Example: Sodium (Na) and Chlorine (Cl).
• Covalent Bond:
  • Sharing of a pair of valence electrons between two atoms.
  • This sharing results in a noble gas electronic configuration.
  • Examples: Hydrogen (H₂) and Methane (CH₄).

Type of Covalent bond

• Polar Covalent Bond:
  • Unequal sharing of electrons leading to a partial positive charge (δ+) on one atom and a partial negative charge (δ-) on the other.
  • Example: H:F.
• Nonpolar Covalent Bond:
  • Equal sharing of electrons between two identical atoms, resulting in no charge separation.
  • Example: F:F.

Electronegativity

• An atom's tendency to attract bonding electrons towards itself, creating a polar charge distribution.
• Periodic Table: Electronegativity values are shown on the periodic table, ranging from low to high.

How To Write and Interpret Structural Formulas

• Different representations of a molecule:
  • Ball-and-stick model: 3D representation with atoms as spheres and bonds as sticks.
  • Electron-dot formula: 2D representation showing atoms and valence electrons as dots.
  • Dash formula: 2D representation showing atoms and bonds using dashes.
  • Condensed formula: Simplified representation showing the order of atoms and associated hydrogens.
  • Bond-line formula: Simplified representation using lines for bonds.

Families of Organic Compounds

• Organic Compounds:
  • Open chain or Aliphatic organic compounds:
    • Alkanes
    • Alkenes
    • Alkynes
  • Closed chain or Cyclic organic compounds:
    • Homocyclic compounds:
      • Alicyclic organic compounds
    • Heterocyclic compounds:
      • Aromatic organic compounds

This quiz covers the fundamental concepts of atomic structure, including atomic number, mass number, subatomic particles, and atomic orbitals. Additionally, it explores types of chemical bonds, such as ionic and covalent bonds. Test your knowledge on these essential chemistry topics!