chemistry

• Unit Conversion


  • Metric system
  • International standard for measurement
  • 7 base units that define 22 derived units with special names and symbols
  • International System of Units (SI)

  
• Conversion Factor


  A fraction in which the numerator and denominator are the same quantity expressed in different units
• Dimensional Analysis


  1. Use conversion factors in problem solving

  2. Allows for a systematic way of tracking units
• Pure Substance


  • Contains only one type of particle and has a fixed constant structure
  • Due to constant composition, it also has a fixed boiling and melting points
• Classifications of Matter


  • Pure Substance
  • Mixture

  
• Element


  • A substance that consists of only one atom
  • Cannot be broken down or transformed into a new substance even by using some physical or chemical means
  • Mostly metals, non-metals or metalloids
• Compound


  • Consists of two or more elements combined chemically in a fixed ratio
  • Can be broken down into separate elements by chemical methods
• Mixture


  • Consists of different kinds of elements and compounds combined physically and not chemically
  • Can be separated into its components using simple means
  • Does not have specific properties like boiling point and melting point
• Homogeneous Mixture


  Concoction whose configuration is comparatively unvarying
• Heterogeneous Mixture


  Concoction whose configuration varies from spot to spot within the sample
• States of Matter


  • Gas
  • Liquid
  • Solid
  • Plasma
• Gas


  • Assumes the shape and volume of its container
  • Particles can move past one another
  • Compressible
  • Lots of free space between particles
• Liquid


  • Assumes the shape of the part of its container
  • Particles can move/slide past one another
  • Not easily compressible
  • Little free space between particles
• Solid


  • Fixed volume and shape
  • Rigid - particles locked into place
  • Not easily compressible
  • Little free space between particles
• Plasma


  • Cloud of ionized particles
  • Electrons separated from the nuclei
  • Found in flames, lightning, and auroras
• Periodic Table


  • Formulated by Dmitri Mendeleev
  • Elements, when arranged in increasing atomic weight, had repeating or periodic properties
  • Elements found in one column share similar properties

  
• Group


  • One column in the periodic table
  • Elements in the same group have the same number of valence electrons

  
• Atomic Number


  Number of protons in the nucleus
• Element Symbol


  One/two letters used to quickly identify the element
• Element Name


  The full name/identity of the element
• Atomic Weight


  The average mass of one atom of the given element in atomic mass units (amu)
• Notable Elements or Types of Elements

  • Hydrogen
  • Alkali Metals
  • Alkaline Earth Metals
  • Transition Metals
  • Metalloids
  • Halogens
  • Noble Gases
• Periodic Trends


  • Ionization Energy
  • Electronegativity
  • Atomic Radius
  • Metallic/nonmetallic character
  • Electron Affinity

  
• Orbital


  • A likely region where electrons would be found around a nucleus
  • Has an associated energy level

  
• Subshells


  Made of multiple orbitals in the same energy level
• Shells


  Made of subshells
• Quantum Numbers


  • Principal Quantum Number (n)
  • Angular Momentum Quantum Number/Azimuthal Quantum Number (l)
  • Magnetic Quantum Number (mₗ)
  • Spin Quantum Number (mₛ)

  
• Electron Configuration Rules


  • Aufbau Principle
  • Hund's Rule of Maximum Multiplicity
  • Pauli Exclusion Principle

  
• Noble Gas Notation


  Shorthand for the electron configuration from 1s² to 4p⁶
• Ions


  Add (anion) or remove (cation) an electron from the count when assigning electron configuration
• Chemical Reaction


  • Interaction between molecules in which the bonds are broken within reactant molecules, and new bonds are formed within product molecules in order to form a new substance
  • Rate of reaction depends on and is affected by factors like pressure, temperature, the concentration of reactants
  • Causes chemical change, i.e. color change, effervescence
• Chemical Equation


  • Nomenclature to express a chemical reaction
  • aA + bB → cC + dD
  • Coefficients (a, b, c, d) are used to balance the equation due to the law of conservation of mass
• Combustion Reaction


  • A combustible material (e.g. hydrocarbons) reacts with an oxidizer (e.g. O₂)
  • Usually involves hydrocarbon and oxygen producing carbon dioxide and water
• Chemical reaction


  Process where reactant molecules are rearranged to form new product molecules in order to form a new substance
• Factors affecting rate of reaction

  • Pressure
  • Temperature
  • Concentration of reactants
• Chemical change


  Changes like color change, effervescence
• Chemical equation


  Nomenclature to express a chemical reaction
• Combustion reaction


  A combustible material (e.g. hydrocarbons) reacts with an oxidizer (e.g. O₂), usually producing carbon dioxide and water
• Hydrocarbon


  Organic compound consisting of hydrogen and carbon
• Synthesis reaction


  Multiple simple compounds combine under certain physical conditions giving out a complex product, opposite of decomposition reaction