Chemistry G.9

• Heterogeneous


  A mixture, in which you can identify all the different parts
• Mixture


  A combination of pure substances where the proportions of the pure substances may vary
• Element


  A pure substance that is made up of one type of atom and that cannot be broken into other substances
• Pure substance


  Made up of particles that are identical, so its chemical and physical properties are constant
• Matter


  Anything that has mass or volume
• Mechanical mixture


  A mixture in which the different substances are visible
• Suspension


  A mixture where the components are in different states
• Compound


  A chemical combination of two or more elements in a fixed ratio
• Homogeneous


  A mixture that looks the same throughout
• Solution


  A mixture in which the separate components are not visible
• Types of mixtures


  • Homogeneous
  • Heterogeneous
• Physical properties


  • Shape/color
  • State
  • Hardness
  • Melting/boiling point
  • Density
• Physical properties can be undone
• Chemical properties


  • Change in color
  • Change in odor
  • Flammability
  • Reaction with acids
  • Reaction with water
• Chemical properties cannot be undone
• Element


  Atom with a specific number of protons that determines the element
• Proton


  Positively charged particle in the nucleus
• Electron


  Negatively charged particle orbiting the nucleus
• Neutron


  Neutral particle in the nucleus
• Atomic number


  Number of protons in the nucleus
• Atomic mass


  Sum of protons and neutrons in the nucleus
• Ion


  An atom with a positive or negative charge
• Compound


  Two or more different elements bonded together
• Molecule


  Two or more elements bonded together, can be the same or different
• Ionic bond


  Bond between a metal and a non-metal
• Molecular bond


  Bond between two non-metals
• Naming molecular compounds


  1. Write name of first element

  2. Write name of second element and change ending to 'ide'

  3. Use prefixes to indicate number of atoms
• Molecular compound names


  • CCl4 - carbon tetrachloride
  • CO2 - carbon dioxide
  • P2O5 - diphosphorus pentoxide
• Naming ionic compounds


  1. Write name of metal element first

  2. Write name of non-metal element second, ending in 'ide'

  3. Don't use prefixes
• Ionic compound names


  • NaCl - sodium chloride
  • LiBr - lithium bromide
• Signs of a chemical reaction include change in temperature, formation of a new substance, change in pH, change in odor
• Chemical reaction equation


  Reactants on left, products on right, separated by arrow
• Chemical reaction equations


  • Ag + Br -> AgBr
  • 4Na + Cl2 -> 2NaCl
• In a chemical reaction, the total mass of the reactants equals the total mass of the products
• Types of chemical reactions

  • Formation
  • Decomposition
  • Replacement
  • Combustion
• Formation reaction


  Two or more elements combine to form a compound
• Formation reactions


  • 2Mg + O2 -> 2MgO
  • 2Na + Cl2 -> 2NaCl
• Corrosion reaction


  Metal reacts with oxygen to form metal oxide, a continuous process
• Corrosion reactions


  • 4Na + O2 -> 2Na2O
• Replacement reaction


  Single replacement: compound reacts with lone element, one compound element is replaced