The fundamental building blocks of matter and atomic theory have shaped our understanding of the physical world.
The structure of atomic particles and nucleus forms the foundation of modern atomic theory. At the center of every atom lies a dense nucleus containing positively charged protons and neutral neutrons, while negatively charged electrons orbit in the surrounding space. This basic arrangement was discovered through groundbreaking experiments, particularly Rutherford's famous alpha scattering experiment and atomic model. When alpha particles were fired at thin gold foil, most passed straight through but some bounced back dramatically, proving that atoms weren't solid spheres but mostly empty space with a concentrated central nucleus.
Building on this discovery, Niels Bohr proposed the Bohr's model energy levels and radioactivity concept that revolutionized atomic theory. His model showed that electrons orbit the nucleus in fixed energy levels or shells, and can only jump between these specific levels by absorbing or releasing precise amounts of energy. This explained why elements emit and absorb specific wavelengths of light and laid the groundwork for understanding radioactivity - the process by which unstable atomic nuclei release particles and energy to become more stable. The electrons in different energy levels also explain chemical bonding and the periodic properties of elements. When atoms gain or lose electrons to achieve stable outer shells, they form ions that can combine into molecules and compounds. This atomic structure and behavior underlies all of chemistry and forms the basis for understanding matter at its most fundamental level.
