Introduction to Organic Chemistry - Aliphatic

Components of the Atom

• An atom consists of protons, neutrons, and electrons.
• The atomic number represents the number of protons in the atom.
• The mass number is the total of protons and neutrons.

Isotopes

• Carbon isotopes differ in mass number (e.g., Carbon-12 and Carbon-13).

Electron Arrangement

• Electrons are arranged in energy levels from lowest to highest.
• Electrons in the ground state have the lowest possible energy.
• Upon absorbing energy, electrons move to a higher energy level (excited state).

Energy Levels and Orbitals

• The number of orbitals in each energy level equals the square of the level number.
• Example: Level 1 contains 1 orbital, level 2 contains 4 orbitals.

Electron Distribution

• Distribution begins from the lowest energy level according to the principles of Aufbau, Pauli, and Hund.
• Aufbau Principle: Electrons fill the lowest energy first.
• Pauli Principle: Each orbital can hold two electrons.
• Hund's Rule: Electrons fill sub-orbitals equally before complete occupation.

Electrons in the Outer Shell

• Electrons in the outer shell are called Valence Electrons.
• These electrons are important for forming chemical bonds.

Ions

• Ions are formed by the loss or gain of electrons, resulting in a positive or negative charge.

Chemical Bonds

• Covalent Bonds: Electrons are shared between atoms.
• Ionic Bonds: Loss and gain of electrons between atoms to form ions.

Electronic Distribution in the Periodic Table

• Elements are distributed based on the number of electrons in the outer shell.
• Isoelectronic elements contain the same number of electrons in the outer shell.

Electron Effect

• Inductive Effect and Resonance Effect explain the behavior of electrons in molecules.

Molecular Attractive Forces

• Attractive forces include hydrogen bonds, dipole interactions, and London forces.

Functional Groups

• Functional groups give distinctive properties to organic compounds.
• Examples: Alcohols (OH), Acids (COOH).

Types of Chemical Reactions

• Substitution, Addition, Elimination, and Rearrangement.

Additional Notes

• Spin movements of electrons are important in electron distribution.
• Skeletal Structure is used to represent compounds chemically.
• Molecular shape is determined by the number of electron groups associated with the central atom.