16-30

• Chemical change is where molecules in a substance change completely, creating a new substance with different properties. Physical change is when the molecules stay the same but the substance's form or state is changed.
• Fe: Iron
• Co: Cobalt
• Ni: Nickel
• Cu: Copper
• Zn: Zinc
• Br: Bromine
• Ag: Silver
• Sn: Tin
• I: Iodine
• Au: Gold
• Hg: Mercury
• Pb: Lead
• Synthesis: Two or more substances combine (a+b=ab)
• Decomposition: A more complex substance breaks down into a simpler one (ab=a+b)
• Single Displacement: An element/compound is switched with another. (ab+c -> ac+b)
• Double Displacement: 2 compounds change (ab+cd -> ac+bd)
• Water - H20
• Sodium chloride - NaCl
• Hydrochloric acid - HCl
• Hydrogen gas - H2
• Oxygen - O2
• Co2 - Carbon dioxide
• NaOH - Sodium hydroxide
• NH3 - Ammonia
• CH4 - Methane
• CaCO3 - Calcium carbonate
• What are reactants and products?

  Reactants are the two elements or compounds that react together to create the product
• What is melting point?


  The temperature at which a substance turns from a solid to a liquid
• What is boiling point?

  The temperature at which a substance changes from a liquid to a gas
• Melting ice: Physical change (state change, from solid to liquid)
• Rusting steel: Chemical change
• Atom: The smallest unit of matter
• Element: A substance made up of only one type of atom that cannot be broken down into smaller parts.
• Compound: A substance made up of two or more elements.
• What are pure substances and can they be elements, compounds or both?

  Pure substances are made up of only one type of particle which can be either an element or compound.
• Brittleness - How easy to break a substance is
• Malleability: Ability to be bent or shaped
• Hardness: How hard an object is
• Ductility: Ability to be stretched