Chemistry essentials

• Periodic Table


  Arrangement of elements by atomic number.
• Atoms


  Neutral particles with equal protons and electrons.
• Metallic Bonds


  Connections between metal atoms in metals.
• Covalent Bonds


  Connections between non-metal atoms in molecules.
• Melting Point


  Higher with greater number of delocalised electrons.
• Non-Metal Elements


  Poor conductors, low melting and boiling points.
• Molecular Formula


  Indicates number of atoms in a molecule.
• Acids


  Non-metal compounds producing H+ ions in solution.
• Ions


  Charged particles from loss or gain of electrons.
• Cations


  Positive ions formed by losing electrons.
• Anions


  Negative ions formed by gaining electrons.
• Ionic Compounds


  Formed from metals and non-metals.
• Hydroxide Ion


  OH-; a common negative ion.
• Carbonate Ion


  CO32-; often insoluble in water.
• Ammonium Ion


  NH4+; a positive molecular ion.
• Nitrate Ion


  NO3-; soluble in water.
• Solubility Rules


  Guidelines for predicting ionic compound solubility.
• Hydrochloric Acid


  HCl (aq); produces chloride ions in solution.
• Sulfuric Acid


  H2SO4 (aq); produces sulfate ions in solution.
• Nitric Acid


  HNO3 (aq); produces nitrate ions in solution.
• Balancing Equations


  Total reactants must equal total products.
• Moles


  Amount of substance measured in grams.
• Reaction with Acids


  Acid + metal -> salt + hydrogen.
• Acid-Base Reaction


  Acid + base -> salt + water.
• Acid-Carbonate Reaction


  Acid + carbonate -> salt + water + CO2.
• Metal Ions


  Positively charged ions from metals.
• Non-Metal Ions


  Negatively charged ions from non-metals.
• Roman Numerals


  Indicate charge size on positive ions.
• Simple Molecules


  Formed by non-metal elements and compounds.