all chem 1

• Atom


  The smallest part of an element that can exist
• There are about a hundred of these atoms shown in the periodic table
• Compound


  A substance formed by chemical reactions where different elements join together in fixed proportions
• Naming ionic compounds


  1. Name of metal

  2. First syllable of non-metal

  3. Add 'ide'
• Naming compounds with oxygen

  1. Name of metal

  2. First syllable of non-metal

  3. Add 'ate'
• Mixture


  Two or more elements or compounds that are not chemically combined together
• Physical processes to separate mixtures

  • Filtration
  • Crystallization
  • Distillation
  • Simple distillation
  • Fractional distillation
  • Chromatography
• Filtration


  • Separates insoluble solids from liquids
• Crystallization


  • Separates soluble substances by evaporating the solvent
• Distillation


  • Separates liquids based on their different boiling points
• Chromatography


  • Separates substances based on how well they are retained by a stationary phase while a mobile phase passes through
• In paper chromatography, the start line must be drawn in pencil and the solvent shouldn't come above that line
• Nuclear model of the atom


  Protons and neutrons in the nucleus, electrons orbiting the outside
• Subatomic particles


  • Protons have a relative mass of 1 and a charge of +1
  • Neutrons have a relative mass of 1 and a charge of 0
  • Electrons have a very small relative mass and a charge of -1
• Atoms are 0.1 nanometers across, with the nucleus being 1/10,000 of the atom's radius
• Isotopes


  Atoms of the same element with the same number of protons but different numbers of neutrons
• Calculating relative atomic mass of a sample with two isotopes

  1. Find percentage of each isotope

  2. Multiply percentage by isotope mass

  3. Add the two results together
• Dalton's atomic model


  Atoms as solid, indivisible spheres
• Thomson's atomic model

  Electrons embedded in a sphere of positive charge
• Rutherford's alpha scattering experiment

  1. Fire alpha particles through gold foil

  2. Most go straight through, some deflected

  3. Evidence for a dense, positively charged nucleus
• Bohr's atomic model

  Electrons orbiting the nucleus in fixed shells
• Periodic table

  • Arranged by atomic number (protons) and atomic mass
  • Groups are columns, periods are rows
  • Metals on the left, non-metals on the right
• Groups in the periodic table

  • Group 1 (alkali metals)
  • Group 2
  • Group 6
  • Group 7
  • Transition metals
• Alkali metals (Group 1)

  • Highly reactive metals with 1 electron in outer shell
• Hydrogen is slightly towards the left of the periodic table despite being a non-metal
• Three specific groups in the periodic table

  • Group one (alkali metals)
  • Group seven (halogens)
  • Group zero (noble gases)
• Alkali metals

  Soft, highly reactive metals with one electron in their outer shell
• Alkali metal reactions

  1. Lose electron

  2. React with oxygen to form metal oxides

  3. React with water to form metal hydroxides

  4. React with chlorine to form metal chlorides
• Halogens

  Group seven elements that all have seven electrons in their outer shell and form diatomic molecules
• Halogens vs alkali metals

  • Halogens gain electrons, become more reactive going up the group
  • Alkali metals lose electrons, become more reactive going down the group
• Noble gases

  • Inert, unreactive elements with full outer shells
  • Used in light bulbs to prevent reactions
• Transition metals

  Block of metals between group 2 and 3, harder and denser than group 1, form ions with different charges, useful as catalysts
• Metallic bonding

  Giant metallic lattice of positive ions surrounded by delocalized electrons
• Properties of metals

  • Good conductors of electricity and heat
  • High melting points
  • Malleable
• Alloys

  Mixtures of metals with atoms of different sizes, distorting the regular rows and making them harder and less malleable
• Ionic bonding

  Formed by transfer of electrons from metals to non-metals, creating positive and negative ions in a giant ionic lattice
• Covalent bonding

  Formed by sharing of electron pairs between non-metal atoms
• Small covalent molecules

  • Hydrogen
  • Chlorine
  • Hydrogen chloride
  • Methane
  • Ammonia
  • Water
  • Oxygen
  • Nitrogen
• Small covalent molecules

  • Gases or liquids with low melting and boiling points due to weak intermolecular forces
• Giant covalent structures

  Substances with thousands of atoms joined by strong covalent bonds, resulting in high melting points