Chemistry Review

• Matter


  Anything that has mass and volume
• Atom


  An individual particle of an element
• Atom


  • The basic unit of a chemical element
  • Made up of tiny sub-atomic particles
• Nucleus


  The dense center of the atom, which gives the atom its mass
• Elements


  A pure substance that is made up of only one type of atom
• Ions


  An atom that has an unequal number of protons and electrons, creating an electric charge
• Cation

  A positively charged ion, having lost electrons
• Anion


  A negatively charged ion, having gained electrons
• Isotopes


  Elements that can have different numbers of neutrons in the nuclei of their atoms
• Metals

  • Shiny, good conductors of heat and electricity, malleable, usually dense and solid at room temperature, readily lose electrons
• Non-metals


  • Dull appearance, poor conductors, usually brittle, less dense, tend to share or gain electrons
• Metalloids


  • Dull or shiny, usually conduct heat and electricity not as well as metals, often malleable, exist in many forms, may gain or lose electrons
• Molecular Compounds

  Made of two non-metals
• Pure Substances

  A substance which is made up of only one kind of materials
• Compound


  A pure substance that is made from two or more elements that are chemically combined
• Mixtures


  A combination of pure substances, where the substances do not combine chemically
• Heterogeneous mixture


  The different parts in the mixture are visible
• Mechanical Mixture


  The different substances that make up the mixture are visible to the naked eye
• Suspension


  The particles of one substance are held within another in a cloudy mixture
• Homogeneous Mixture

  All parts of the mixture look the same, no separations visible
• Solutions


  The different substances that make up the mixture are not individually visible, one substance is dissolved into another
• Atom


  • Protons and neutrons are located in the nucleus
  • Electrons are located on energy shells around the nucleus
  • Protons have a positive charge
  • Neutrons are neutral, they have no charge
  • Electrons have a negative charge
• Dalton described the atom as a solid indivisible sphere, and all atoms of an element are identical in their properties
• Thompson said the sphere of the atom was positively charged and that electrons were scattered throughout it, called the "plum pudding model"
• Rutherford discovered that the positive charge was only in the center of the atom, which he called the nucleus, and that most of the atom was empty space with electrons circling the nucleus
• Chadwick proposed that the nucleus also contains neutral particles called neutrons
• Bohr discovered that the electrons orbited the nucleus at certain energy levels and that each energy level could only fit a certain number
• Element


  A substance that cannot be broken down into simpler substances by chemical means, defined by the number of protons it has
• Placement of elements on the periodic table

  • Metals are found on the left side of the staircase
  • Metalloids are found along the staircase but not aluminum
  • Non-Metals are found on the right side of the staircase (plus hydrogen)
• Physical properties


  Characteristics of a substance that we observe or measure without changing the identity of that substance, such as smell, colour, texture, hardness, state, melting point, and boiling point
• Chemical properties


  Characteristics that we observe or measure only by changing the identity of the substance through a chemical reaction
• Physical change


  The appearance or form of matter changes but the kind of matter in the substance does not
• Chemical change


  The kind of matter changes and at least one new substance with new properties are formed
• Indications a chemical change has occurred

  • Change in colour or odor
  • Formation of a precipitate
  • Light is given off
  • Gas bubbles formed
  • Change in heat
• WHMIS Symbols

  • Flame over circle: oxidising, adds oxygen to fire
  • Flame: Flammable, can set on fire easily, self heating
  • Exploding bomb: Explosive, will explode, self reactive
  • Gas Cylinder: Gas under pressure
  • Skull and Crossbones: Acute toxicity, will cause extreme damage
  • Corrosion: serious eye damage, skin corrosion, corrosive to metal
  • Biohazardous: Biohazardous Infectious Material, could be infectious
  • Health Hazard: carcinogenicity, respiratory sensitication reproductive toxicity, target organ toxicity, germ cell mutagenicity
  • Exclamation Mark: irritation, Skin sensitization, acute toxicity, specific target organ toxicity, hazardous to the ozone layer
  • Environment: Aquatic toxicity
• In 1807, Sir Humphrey Davy discovered a new element: Potassium, which is found in potash.
• Lavoisier defined an element as a substance that could not be decomposed by existing chemical means.
• Who debunked phlogiston?

  Lavoisier had shown that phlogiston didn't exist.