chemisty topic 1

Cards (33)

  • The periodic table is a list of all the elements which are known to exist
  • Elements
    A single type of atom
  • Atoms
    Very very small things
  • The name 'atom' comes from the Greek word for 'uncuttable'
  • Compound
    Two or more elements that are chemically bonded together
  • Structure of an atom
    • Electrons on the shells around the outside
    • Protons in the middle
    • Neutrons in the middle
  • Nucleus
    The part in the middle of an atom
  • Protons
    • Mass of 1
    • Charge of +1
  • Neutrons
    • Mass of 1
    • Charge of 0
  • Electrons
    • Mass of 1/1000
    • Charge of -1
  • Atomic number
    The number of protons and electrons in an atom
  • Mass number
    The number of protons plus the number of neutrons
  • Important chemical formulas to learn
    • Water (H2O)
    • Hydrogen gas (H2)
    • Oxygen gas (O2)
    • Carbon dioxide (CO2)
    • Ammonia (NH3)
    • Hydrochloric acid (HCl)
    • Sulfuric acid (H2SO4)
  • Pure substance
    A substance made of only that type of element or compound
  • Compound
    Two or more different elements chemically bonded together
  • Mixture
    Lots of different things, some chemically bonded, some not
  • Separation techniques
    • Distillation
    • Evaporation
    • Filtration
    • Fractional distillation
  • The plum pudding model was the original model of the atom
  • Rutherford's experiment led to the discovery of the nucleus
  • Bohr developed the current model of the atom
  • Chadwick discovered neutrons
  • Groups
    Go down the periodic table, tell us the number of electrons on the outer shell
  • Periods
    Go across the periodic table, relate to the number of shells
  • Determining the electronic configuration of an element
    1. Look up the element on the periodic table
    2. Determine the number of shells from the period
    3. Determine the number of electrons on the outer shell from the group
  • Atomic number
    The number of protons in the nucleus
  • Charge of an ion
    • Metals lose electrons, become positive ions
    • Nonmetals gain electrons, become negative ions
  • Groups on the periodic table
    • Group 1 (alkali metals)
    • Group 2 (alkaline earth metals)
    • Group 6 (chalcogens)
    • Group 7 (halogens)
    • Group 8 (noble gases)
    • Transition metals
  • Mendeleev left gaps in his periodic table, which allowed him to predict undiscovered elements
  • Halogens
    • Exist as diatomic molecules
    • Highly reactive, want to gain 1 electron
    • Reactivity decreases down the group
  • A more reactive element
    Can displace a less reactive element from a compound
  • Displacement reactions
    Reactions where a more reactive element displaces a less reactive element from a compound
  • Alkali metals
    • Soft, grey metals
    • Highly reactive with water, forming metal hydroxides and hydrogen gas
    • Reactivity increases down the group
  • Transition metals
    • Hard, shiny, good conductors
    • Used in jewelry, wires, saucepans, stained glass, statues