Chemistry

• Evidence of chemical change

  • Heat is produced/absorbed
  • Change in pH (acidicity)
  • Starting material is used up
  • Change in colour (some exceptions)
  • gas bubbles form in a liquid
  • a solid forms in a liquid (precipitate)
• Physical Properties


  any property that Can Describes how a substance
• Chemical Properties


  inteacts with other substances
• Chemical Change


  • Substance changes Composition
  • Is a new substance formed?
  • Is the change typically reversible?
• Physical Change


  • Substance Changes form/State
  • NO new substance formed
  • Is the change typically yes reversible?
• Homogenous Mixture


  Looks like one Substance (uniform)
• Heterogeneous Mixture


  Can see the different parts
• Suspension


  • clouty mixture in which particles are suspended in another substance and can be filtered out
  • Will Settle over time
• Colloid


  Cloudy mitture but the particles are so small that they cannot be filtered out (easily)
• Mixture


  Combination of pure substances
• Pure Substance


  • Elements
  • Compounds
  • Cannot be broken down into Simpler Parts
  • Building block "for other matter
• Matterall matter is made of tiny particles called atoms

  • have different properties that can "combine" together
• Atoms


  The basic building blocks of matter
• Particle Model of Matter


  • all matter is made up of tiny Particles
  • there are spaces between these particles
  • Particles are attracted to one another
  • Particles are always moving
  • Particles move faster + further apart when they gain energy (heat)
• Ionic Bond


  Electrons are transferred between a Metal and a non-metal
• Molecular/Covalent Bond


  Electrons are shared between two non-metals
• Compound


  2 or more different chemical substances (elements) bonded together
• Protons


  positively charged particles found in the nucleus
• Neutrons


  neutral particles found in the nucleus
• Electrons


  negatively charged particles that orbit the nucleus
• Atomic symbol


  reposents the element's name (e.g carbon)
• Atomic number


  represents the number of protons in the nucleus (note that in a neutral atom, the atomic number of protons is also equal to the number of electrons)
• Atomic mass


  represents the weighted average (in g/mol) of the masses of each naturally occurring isotope of the element
• Atomic Models


  • Dalton's Model
  • Thompson's "Plum Pudding" Model
  • Hantaro Nagaoka "Satumian model"
  • Rutherford's "Nuclear" Model
  • Bohr's Atomic Model
• Dalton's Model


  • Suggests matter is made up of Clements
  • Looks like a Smal Solid sphere
  • ada each element had its own mass
• Thompson's "Plum Pudding" Model

  • Said positively charged spiere With negative elections emboles in the sphere
  • The positive and negative components balanced each other out
• Hantaro Nagaoka "Satumian model"


  • Electrons (negative charges) orbited a positively charged sphere
  • boks like Saturn
• Rutherford's "Nuclear" Model


  • Atom with mostly empty Space
  • nucleus in the Center
  • (-) charged electrons Scattered around riddleus
  • Like a pea in a football field
• Bohr's Atomic Model


  • elections orbit the nuclees in fixed "pathways"
  • protons & neutrons in nucleus
  • Like a miniature solar system
• The Atomic Theory has been revised many times throughout history
• Ionic Compounds


  • Ionic metal + a non melal
  • The first element should be a metal
  • electrical Current will be present
  • Solid at room temperature
  • Dissolve in water (Solubility)
• Naming Ionic Compounds


  • The name includes both names of the element in the compound, with the name of the metal listed first
  • The non-metal element is listed second, and it;s ending is changed to "ide"
• Reaction Rate


  A measure of how fast a reaction occurs, and is typically determined by assessing the amount of energy released over a given period of Reaction rate
• Ways to speed up/slow down the rate of a chemical reaction

  • Catalyst
  • Temperature
  • Concentration
  • Surface Area
• Catalyst


  • Substances that help a reaction proceed quicker
  • not con sumed by reaction
  • enzymes - Catalyst
• Types of Chemical Waste

  • Non-persistent
  • Persistent
• Ionic compound


  Ionic metal + a non metal
• Ionic compounds


  • Solid at room temperature
  • Dissolve in water (Soluble)
• Naming ionic compounds


  1. Name includes both elements in the compound, with the metal listed first

  2. The non-metal element is listed second, and its ending is changed to "ide"
• Reaction rate


  Measure of how fast a reaction occurs, typically determined by assessing the amount of energy released over a given period