Atomic Structure - Chemistry Short Notes 📚

The fundamental building block of all matter is the atom. Understanding its structure is crucial to comprehending the behavior of elements and their interactions in chemical reactions. Here's a concise overview of atomic structure:

Subatomic Particles

  1. Protons: Positively charged particles located in the central core called the nucleus. The number of protons determines the element's identity (atomic number).
  2. Neutrons: Uncharged particles also residing in the nucleus. Their number contributes to the atom's mass (atomic mass).
  3. Electrons: Negatively charged particles that orbit the nucleus in distinct energy levels. Electrons are responsible for chemical bonding and various atomic properties.

Atomic Structure - Atomic Models

Our understanding of atomic structure has evolved through various models:

  1. Dalton's Model (1803): Proposed atoms as indivisible spherical particles.
  2. Thomson's Plum Pudding Model (1904): Electrons embedded in a positively charged sphere like plums in a pudding.
  3. Rutherford's Model (1911): Dense, positively charged nucleus with electrons orbiting at a distance, like planets around the sun. This explained the gold foil experiment, but couldn't account for electron stability.
  4. Bohr's Model (1913): Electrons occupy specific energy levels (orbits) around the nucleus, quantized by angular momentum. Electrons can jump between levels by absorbing or releasing energy (photons). This explained the stability of electron orbits and laid the foundation for quantum mechanics.
  5. Quantum Mechanical Model (Present): Electrons exist in orbitals, defined by probability distributions rather than precise paths. This model, though complex, provides the most accurate understanding of atomic structure and behavior.
    Atomic Structure - Chemistry Short Notes

Atomic Structure - Key Concepts:

  1. Electron Configuration: Arrangement of electrons in orbitals, determining an element's chemical properties.
  2. Valence Electrons: Electrons in the outermost energy level, mainly involved in bonding.
  3. Quantum Numbers: Define the state of an electron in an orbital (principal, angular momentum, magnetic, spin).
  4. Periodic Trends: Atomic properties vary predictably across the periodic table based on electron configuration.

Atomic Structure - Significance:

Understanding atomic structure is essential for various fields, including:

  1. Chemistry: Predicting reactivity, bonding behavior, and properties of elements and compounds.
  2. Materials Science: Designing new materials with desired properties.
  3. Nanotechnology: Manipulating matter at the atomic and molecular level.
  4. Biology: Understanding biochemical processes and interactions.
Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes

Atomic Structure - Chemistry Short Notes