Chemistry Atomic Structure and Bonding

Chemistry

Atomic Structure

• Atom: smallest unit of matter, consisting of protons, neutrons, and electrons
• Protons: positively charged, found in nucleus, determine atomic number
• Neutrons: no charge, found in nucleus, determine atomic mass
• Electrons: negatively charged, found in electron cloud, participate in chemical reactions

Chemical Bonding

• Types of bonds:
  • Ionic bonds: transfer of electrons between atoms
  • Covalent bonds: sharing of electrons between atoms
  • Hydrogen bonds: weak attraction between atoms
• Bonding theories:
  • Valence Shell Electron Pair Repulsion (VSEPR) theory: predicts molecular shape
  • Molecular Orbital (MO) theory: describes molecular bonding and antibonding

Chemical Reactions

• Types of reactions:
  • Synthesis: combination of reactants to form a product
  • Decomposition: breakdown of a reactant into products
  • Single displacement: one element replaces another in a compound
  • Combustion: reaction involving oxygen and heat
• Reaction rates:
  • Factors affecting reaction rates: concentration, temperature, catalysts, surface area
  • Rate equations: describe the rate of a reaction

Physics

Mechanics

• Kinematics: study of motion without considering forces
  • Describing motion: position, velocity, acceleration, displacement
  • Types of motion: linear, circular, rotational
• Dynamics: study of motion with forces
  • Newton's laws:
    • First law: inertia, objects at rest or in motion remain so unless acted upon by a force
    • Second law: force and acceleration, F = ma
    • Third law: action and reaction, every action has an equal and opposite reaction

Energy and Work

• Types of energy:
  • Kinetic energy: energy of motion
  • Potential energy: energy of position or state
  • Thermal energy: energy of heat
  • Electromagnetic energy: energy of light and radiation
• Work: transfer of energy from one object to another
  • Work-energy theorem: work done on an object is equal to the change in its kinetic energy

Thermodynamics

• Laws of thermodynamics:
  • Zeroth law: temperature, if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other
  • First law: energy conservation, energy cannot be created or destroyed, only converted
  • Second law: entropy, total entropy of a closed system always increases over time
  • Third law: absolute zero, it is impossible to reach absolute zero by any finite number of processes

Atomic Structure

• Atom: the smallest unit of matter, composed of protons, neutrons, and electrons
• Protons: positively charged, found in the nucleus, determine the atomic number of an element
• Neutrons: have no charge, found in the nucleus, contribute to the atomic mass of an element
• Electrons: negatively charged, found in the electron cloud, participate in chemical reactions and bond formation

Chemical Bonding

• Ionic bonds: form through the transfer of electrons between atoms, resulting in ions with opposite charges
• Covalent bonds: form through the sharing of electrons between atoms, resulting in a molecule
• Hydrogen bonds: weak attractions between atoms, important in molecular structure and function
• Valence Shell Electron Pair Repulsion (VSEPR) theory: predicts molecular shape based on electron pair arrangement
• Molecular Orbital (MO) theory: describes molecular bonding and antibonding, including sigma and pi bonds

Chemical Reactions

• Synthesis reactions: combine reactants to form a new product
• Decomposition reactions: break down a reactant into multiple products
• Single displacement reactions: one element replaces another in a compound
• Combustion reactions: involve oxygen and heat, resulting in a chemical change
• Reaction rates: influenced by factors such as concentration, temperature, catalysts, and surface area
• Rate equations: mathematical expressions describing the rate of a reaction

Physics

Mechanics

• Kinematics: describes motion without considering forces, including position, velocity, acceleration, and displacement
• Dynamics: studies motion considering forces, including Newton's laws of motion
• Newton's first law: an object at rest or in motion remains so unless acted upon by an external force
• Newton's second law: force is proportional to acceleration, F = ma
• Newton's third law: every action has an equal and opposite reaction

Energy and Work

• Kinetic energy: energy of motion, dependent on an object's velocity
• Potential energy: energy of position or state, dependent on an object's position or configuration
• Thermal energy: energy of heat, transferred between systems
• Electromagnetic energy: energy of light and radiation, including visible and non-visible forms
• Work: transfer of energy from one object to another, quantified by the work-energy theorem

Thermodynamics

• Laws of thermodynamics:
  • Zeroth law: thermal equilibrium, allowing temperature measurement
  • First law: energy conservation, energy cannot be created or destroyed, only converted
  • Second law: entropy, total entropy of a closed system always increases over time
  • Third law: absolute zero, impossible to reach by any finite number of processes

Learn about the building blocks of matter, including atomic structure and different types of chemical bonds. Understand the roles of protons, neutrons, and electrons, and how they form ionic and covalent bonds.