4Q Chemistry LT Reviewer

• Element


  Only one atom that cannot be divided
• Compound


  2 or more elements
• Elements and compounds are both pure substances
• Pure substance


  Element or compound that cannot be separated physically
• Mixture


  Mixture of 2 or more substances that CAN be separated physically
• Types of mixtures


  • Homogenous (cannot see the mixture)
  • Heterogenous (can see the mixture)
• There are 118 known elements and 3 unknown elements
• Dmitri Mendeleev


  Father of the periodic table, since he finalized the arrangement of elements
• The periodic table is organized according to the element's properties
• Groups in the periodic table

  • Group A (Representative elements)
  • Group B (Transition elements)
• Supersaturated


  Contains more undissolved solute than saturated solution because of its tendency to crystallize and precipitate
• Percent Concentration


  Composition of solution is defined in terms of concentrations. Formula: Percentage = mass/volume over mass/volume of solution x 100%. To get the denominator, add the solute and solvent. Unless the question states its already combined then just divide. Round off to 2 decimal places and answer will be percentage.
• Acid


  Tastes sour, corrosive, turns blue litmus paper to red and pH level is less than seven
• Base


  Tastes bitter, slippery, turns red litmus paper to blue, and pH level is more than 7
• Water is 7 = neutral
• Acids


  • Batteries
  • Citric foods
  • Soda
• Bases


  • Soap
  • Cleaners
• Transuranium


  Bigger atomic mass and emit radiation. Found at the last 2 periods
• Periods


  Horizontal rows in the periodic table. Elements in periods have no similar properties
• Families


  Vertical rows in the periodic table. Elements in families have similar properties
• Example of element: 92 - atomic number, U - symbol, Uranium - name, 238.0 - atomic mass
• Major divisions of the periodic table

  • Nonmetals
  • Metals (75% of the periodic table)
  • Metalloids (half metal)
• Metals


  • High density, hard, ductile, high melting points, good conductors of heat and electricity and lustrous
• Nonmetals


  • Low density, brittle, low melting points, poor conductors of heat and electricity
• Metalloids


  • Conduct heat and electricity at varied points, varied density, varied melting points, some are shiny
• Types of solutions


  • Gaseous (solvent is GAS)
  • Liquid (solvent is LIQUID)
  • Solid (solvent is SOLID)
• Saturated


  Solute dissolves until unable to dissolve anymore, leaving undissolved substance at the bottom
• Unsaturated


  Completely dissolves