Overview

This topic explores the fundamental structure of atoms, including subatomic particles and how atoms change during nuclear reactions. It introduces basic atomic theory, isotopes, radioactivity, and the differences between nuclear fission and fusion.

Key Concepts and Atomic Principles

• Atom: The basic unit of matter, composed of protons, neutrons, and electrons.
• Subatomic Particles: Protons (positive), neutrons (neutral), and electrons (negative). Protons and neutrons are in the nucleus; electrons orbit the nucleus in shells.
• Atomic Number: Number of protons in an atom; determines the element.
• Mass Number: Total number of protons and neutrons.
• Isotopes: Atoms of the same element with different numbers of neutrons (e.g., carbon-12 and carbon-14).
• Radioactivity: The spontaneous emission of particles or energy from an unstable nucleus. Types include alpha, beta, and gamma radiation.
• Half-Life: The time it takes for half of a radioactive substance to decay. Used in carbon dating.
• Nuclear Fission: Splitting of a large nucleus into smaller nuclei, releasing energy (used in nuclear power and atomic bombs).
• Nuclear Fusion: Combining of small nuclei to form a larger one, releasing even more energy (powers the sun and hydrogen bombs).
• Electron Configuration: The arrangement of electrons in an atom. Helps explain chemical behavior and periodic trends.

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