Atomic Structure Basics

Atomic Structure

• An atom consists of three main parts:
  • Protons: positively charged particles in the nucleus (center)
  • Neutrons: particles with no charge in the nucleus
  • Electrons: negatively charged particles orbiting the nucleus
• Atomic number (Z): number of protons in an atom's nucleus, which determines the element
• Mass number (A): total number of protons and neutrons in an atom's nucleus

Electron Configurations

• Electron shells: energy levels around the nucleus where electrons occupy
  • Shells are divided into subshells (s, p, d, f) with specific capacities
• Aufbau principle: electrons occupy the lowest available energy level
• Pauli's exclusion principle: no two electrons in an atom can have the same set of quantum numbers
• Hund's rule: electrons occupy degenerate orbitals with parallel spin before pairing up

Atomic Interactions

• Electromagnetic force: attraction between oppositely charged particles (protons and electrons)
• Strong nuclear force: attraction between protons and neutrons in the nucleus
• Weak nuclear force: responsible for certain types of radioactive decay
• Ionization energy: energy required to remove an electron from an atom
• Electron affinity: energy released when an electron is added to an atom

Quantum Mechanics

• Wave-particle duality: electrons exhibit both wave-like and particle-like behavior
• Heisenberg's uncertainty principle: impossible to know both position and momentum simultaneously
• Schrödinger equation: mathematical equation describing the behavior of electrons in an atom
• Orbitals: probability distributions of electrons in an atom

Spectroscopy

• Atomic spectra: patterns of light emitted or absorbed by atoms
• Emission spectra: light emitted when electrons transition to a lower energy state
• Absorption spectra: light absorbed when electrons transition to a higher energy state
• Spectral lines: specific wavelengths of light corresponding to energy transitions

Atomic Structure

• An atom consists of three main parts: protons, neutrons, and electrons
• Protons are positively charged particles in the nucleus (center) of an atom
• Neutrons have no charge and are found in the nucleus
• Electrons are negatively charged particles that orbit the nucleus

Atomic Number and Mass Number

• Atomic number (Z) is the number of protons in an atom's nucleus, determining the element
• Mass number (A) is the total number of protons and neutrons in an atom's nucleus

Electron Configurations

• Electron shells are energy levels around the nucleus where electrons occupy
• Shells are divided into subshells (s, p, d, f) with specific capacities
• Aufbau principle: electrons occupy the lowest available energy level
• Pauli's exclusion principle: no two electrons in an atom can have the same set of quantum numbers
• Hund's rule: electrons occupy degenerate orbitals with parallel spin before pairing up

Atomic Interactions

• Electromagnetic force: attraction between oppositely charged particles (protons and electrons)
• Strong nuclear force: attraction between protons and neutrons in the nucleus
• Weak nuclear force: responsible for certain types of radioactive decay
• Ionization energy: energy required to remove an electron from an atom
• Electron affinity: energy released when an electron is added to an atom

Quantum Mechanics

• Wave-particle duality: electrons exhibit both wave-like and particle-like behavior
• Heisenberg's uncertainty principle: impossible to know both position and momentum simultaneously
• Schrödinger equation: mathematical equation describing the behavior of electrons in an atom
• Orbitals: probability distributions of electrons in an atom

Spectroscopy

• Atomic spectra: patterns of light emitted or absorbed by atoms
• Emission spectra: light emitted when electrons transition to a lower energy state
• Absorption spectra: light absorbed when electrons transition to a higher energy state
• Spectral lines: specific wavelengths of light corresponding to energy transitions