Science 9

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Science 9 Matter and Chemical Change

• A Brief Unit Review

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Topic 1 Exploring Matter

• Particle Model of Matter
• All matter is made up of tiny particles that are
  always moving. More energy, more movement. In a
  pure substance the particles are the same.
  Particles have attractive forces between them.
  Particles have spaces between them.
• States of Matter
• Classification of Matter
• Matter ? Pure Substace ? Elements or Compounds
• Lgt Mixtures ? Homogeneous (solution) or
  Heterogeneous

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Topic 2 Changes in Matter

• Physical Changes
• The particles stay the same but their physical
  appearance may have changed.
• Can be reversed easily.
• Example Change in State
• or Dissolving

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Topic 2 Changes in Matter

• Chemical Change
• Difficult/Impossible to reverse
• A reaction
• New products are formed (bubbles, precipitate,
  new odor)
• Other evidence Colour change, release of heat
  (exothermic), heat is absorbed (endothermic).
• Example Combustion, acid-base neutralization.

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Topic 2 Changes in Matter

• Physical Properties of Matter
• color, texture, lustre, smell, state, melting
  point, boiling point, hardness, malleability,
  ductility, crystal shape, viscosity, solubility,
  density and conductivity (electrical and heat).
• Chemical Properties of Matter
• reaction with water/air/acids/heat, ability to
  burn (combustibility), toxicity, stability.

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Topic 3 Elements

• Law of Conservation of Mass
• In a chem. rxn, mass of the products mass of
  the reactants
• Law of Definite Composition
• In compounds, atoms arrange themselves in defined
  ratios. For example in water, there are 2
  hydrogen atoms for every oxygen atom.
• Atomic Theory (Dalton)
• All matter is made up of atoms
• Atoms cannot be created/destroyed/divided into
  smaller particles.
• Atoms of the same element are identical in size
  and mass. Different elements have different
  sized atoms.
• Atoms combine to form compounds.

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Topic 3 - Elements

• Atomic Models
• Raisin Bun/Plum Pudding Model (Thompson)
• Planetary Model (Rutherford)
• Atomic Model (Bohr)
• Electron-Cloud/Quantum Model

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Topic 4 5 The Periodic Table of Elements
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Topic 4 5 The Periodic Table

• Mendeleev assembled the periodic table by
  increasing atomic mass.
• Each element has an atomic number. This is the
  of protons an element has in its nucleus.
• Each element as a symbol, eg. A for Argon
• Each element has a mass number. This is the of
  protons and neutrons it has.

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Topic 6 - Compounds

• Ionic Compounds
• Metal Non metal.
• Each atom becomes an ion (charged particle) in
  solution.
• Therefore they are conductive when
  liquid/aqueous.
• Very soluble in water.
• Solids at room temp.
• Example NaCl

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Topic 6 - Compounds

• Molecular Compounds
• Non-metal Non-metal
• Non conductive in solution
• Example
• H2O
• O2 (diatomic molecule)
• CO2

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Topic 6 - Compounds

• Naming Compounds
• Write the name of the first element.
• Write the name of the second element, but change
  the ending to -ide. For example, oxygen becomes
  oxide, fluorine becomes fluoride.
• IF YOUR COMPOUND IS IONIC, youre done!
• IF YOUR COMPOUND IS MOLECULAR, add a prefix
  (mono, di, tri, tetra) to each atom to indicate
  the quantity.
• Example H2O
• Dihydrogen monoxide

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Topic 7 Chemical Reactions

• Reactants ? Products
• Bonds break (releases energy) and reform (uses
  energy).
• Exothermic rxns give off extra energy, as heat.
• Endothermic rxns absorb energy (gets cooler)

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Topic 8 Reaction Rate

• Catalysts increase the rate of reaction. A
  common example are enzymes in your digestive
  system.
• Inhibitors slow down reactions.
• Corrosion is the oxidation of metals (ex. Rust
  iron oxygen ? iron oxide/rust). To prevent
  corrosion, we plate our metals (galvanization is
  zinc plating).
• Combustion Fuel oxygen ? carbon dioxide
  water energy