Atomic Structure

A. Subatomic Particles and Atomic Models Definition: Atoms consist of three fundamental subatomic particles: protons (positive charge), neutrons (neutral), and electrons (negative charge). Various atomic models have been proposed to explain atomic structure, including Thomson's plum pudding model and Rutherford's nuclear model. Explanation: Atoms are the basic building blocks of matter, composed of a central nucleus containing protons and neutrons, surrounded by electrons in energy levels. The discovery of cathode rays led to the identification of electrons, while Rutherford's gold foil experiment revealed the existence of a dense, positively charged nucleus. These discoveries revolutionized our understanding of atomic structure, showing that atoms are mostly empty space with a tiny, massive nucleus at the center. The arrangement of these particles determines the chemical properties of elements.