Chem Mod 1 Ch 2 Properties of Matter

• Matter


  Anything that has mass and occupies space
• Atom


  The smallest unit of an element
• Subatomic particles


  The tiny particles which are found inside an atom (protons, neutrons and electrons)
• Elements


  Fundamental materials of which all matter is composed, containing just one type of atom. They can't be broken down into simpler substances
• Monatomic elements


  Elements made up of only one atom
• Molecule


  A group of two or more atoms held together by chemical bonds (all compounds are molecules but not all molecules are compounds)
• Compounds


  Materials containing different atoms which have reacted together and bonded together chemically in fixed ratios
• Mixtures


  Contains two or more substances that are not chemically combined
• Model


  A description that scientists use to represent the important features of what they are trying to describe, they are able to test the consistency of their observations against various predictions of the model
• Atomic Theory of Matter


  1. All matter is made up of tiny spherical particles which are indivisible and indestructible

  2. Atoms are made up of even smaller subatomic particles
• Mixtures


  • Contains two or more substances that aren't chemically combined
  • Homogenous: Composition is the same throughout the mixture (even distribution)
  • Heterogenous: Composition varies throughout the mixture (uneven distribution)
  • Can be separated physically using the properties of the substances through various techniques
  • Little to no energy change as substances aren't chemically bonded together
  • Varying compositions and formula (no fixed ratio)
• Solutions


  • A homogenous mixture which has one or more solutes (the substance that dissolves in solvent) dissolved in a solvent (the substance in which the solute dissolves)
  • The solvent is always present in a greater amount than the solute
  • Can be dilute or concentrated
  • Saturated or unsaturated
  • Aqueous solution: A solution with water as the solvent
• Calculating percentage composition


  1. Percentage Composition of Compounds (by mass of element): (mass of element / mass of compound) x 100

  2. Mass of Component: (component % x mass of mixture) / 100

  3. Mass of Element: (element % x mass of compound) / 100
• Suspensions


  • Heterogenous
  • Suspended particles seen by the naked eye
  • The suspended particles scatter the light, making them opaque
  • Particles settle down to the bottom when undisturbed
• Colloids


  • Fine particles spread throughout
  • Dispersed phase, dispersion medium
• Solids


  • Definite shape and volume
  • Strong forces of attraction – particles in fixed positions
  • Particles vibrate around fixed axes (dynamic)
• Liquids


  • Fluid: No definite shape (takes shape of container)
  • Definite volume
  • Particles have a weaker attraction – are free to move over each other
• Gases


  • Fluid: No definite shape (fills shape of container)
  • No definite volume (doesn't occupy a set amount of space)
  • Very weak forces of attraction – move in random motion
  • Highly compressible
• Changes of State


  1. Increase in temp causes particles to gain more energy and vibrate more vigorously, allowing them to overcome the forces of attraction and change state from solid-liquid or liquid-gas

  2. Decrease in temp causes the particles to lose energy as they can no longer overcome the forces of attraction they change state from gas-liquid or liquid-solid

  3. When a substance changes from a solid to a gas without becoming a liquid, all forces between the particles have been broken, resulting in sublimation
• Filtration


  1. Solid particles in a fluid are removed using a filter medium, allowing the fluid to pass through but retaining the solid particles

  2. Filtrate = Clarified fluid

  3. Residue = Solid particles
• Evaporation


  1. Separating liquids and solids from a solution by allowing the water to evaporate into the air

  2. More concentrated solution/solid precipitate of dissolved solution

  3. Residue = solid left behind
• Decanting


  1. Separates mixtures of immiscible liquids or of a liquid and solid mixture (components must have different densities) through the use of gravity by pouring off the lighter component

  2. Pure, solid end product

  3. Liquid above solid as a supernate / is supernatant
• Distillation


  1. Separates a liquid from a mixture of liquids with different boiling points by heating the mixture to the boiling point of your chosen liquid and immediately condensing the resulting vapours

  2. Complete separation = nearly pure components

  3. Partial separation = increasing the concentration
• Fractional Distillation


  Separates a liquid from a mixture of liquids whose boiling points are similar by heating the mixture to the boiling point. A column is heated with the temp increasing up the column, particles then condense at their boiling point and are led away, separating the various components
• Chromatography


  Separates a mixture of chemical substances into its individual components where molecules in a mixture are placed onto a material and are separated as they travel at different speeds with those smaller, less sticky ones travelling faster and the larger, sticker ones moving slower
• Sedimentation


  Separates solids suspended in liquid by allowing gravity or a centrifugal force to separate the mixture into components based on densities
• Properties of Metals


  • Usually solid at room temp, lustrous, malleable, ductile, silver-coloured, dense, high melting/boiling point, high tensile strength, good conductors of heat and electricity
• Properties of Non-metals


  • Not malleable, not ductile, dull in colour, not dense, lower melting/boiling point, poor conductors of heat and electricity
• Properties of Metalloids


  No generally accepted definition nor characteristics that make a metalloid
• Physical Properties


  • Melting point
  • State of matter
  • Thermal conductivity
  • Odour
  • Viscosity
  • Texture
  • Magnetism
  • Density
  • Solubility
  • Colour
  • Boiling point
  • Malleability
  • Hardness
  • Ductility
  • Electrical conductivity
  • Lustre
• Chemical Properties


  • Reactivity
  • Toxicity
  • Oxidation
  • pH
  • Corrosion
  • Radioactivity
  • Flammability
• Physical Change


  • Composition remains the same (molecules rearranged)
  • Only affects physical properties
  • Involves little to no absorption or production of energy
  • Temporary change
  • Easily reversible (original substance can be recovered)
• Chemical Change


  • Molecular composition is changed entirely (involves the formation of new substances)
  • Changes both physical and chemical properties
  • During chemical reaction, energy is taken in (absorbed) or given off (produced)
  • Permanent Change
  • Irreversible (original substance can't be recovered)