Elements:  fundamental building block of all kinds of matter (solids, liquids, gases, etc.)

    elements bond together with either like elements, different elements, or both to make molecules

            ex:   (“molecular oxygen”, usually a gas);  (gas, liquid, solid),  hydroxyl, …

            the number of atoms/elements is written below and to the right of the element symbol

                    if only 1 atom/element is in the molecule, the one is usually left off
                    ex:    NB: 

   
ions:  charged elements or charged molecules (either positive or negative charge, not neutral)

            ex:     ex: 

            the charge is written above and to the right on charged elements and/or molecules

    cation:  element/molecule with positive charge;  anion:  element or molecule with negative charge

            cations are “missing” electrons (therefore +ve), anions have extra electrons (therefore –ve)

                    ex:   1 “extra” electron beyond magic # of 10, discards electron, becomes

                    ex:   1 “less” electron than magic # of 18, steals electron, becomes

 

    Chemical bonds: 3 major ways of joining two atoms together into (usually) stable union

            the “big goal” is to lower energy of system, lowest energy configuration = most stable = neutral

    1.  ionic bonds:  anion bonded to a cation.  –ve ion gives up extra electron/s to +ve ion = neutral

            ex:  , 

   
    2.  covalent bonds: electrons shared “simultaneously” between two elements/molecules

                    two people with 50 cents each pool resources so both have one dollar

                    only makes sense if two people hang together all the time, act like one person

            ex: 

   
    3.  metallic bonds:  electrons shared among all atoms, the Communist approach to bonding

            ex:  magnesium  has 2 “extra”electrons in level 3, gives them up, big electron cloud

 

States of Matter:  depends on how atoms/elements arranged in space, not really on physical properties

    solids:  orderly uniform repeated arrangement of atoms. “long range order”.  ice, crystals, metals,…

    liquids: somewhat random arrangement of atoms, “short range order” only.  water, glass, magma….

    gases:  highly disordered, dispersed, space between molecules.  water vapor, , argon….

    plasma:  both electrons and nuclei floating free (ionic soup).  Sun, ionosphere surrounding Earth

 

    Chemical Reactions:  bake a cake.  reactants (ingredients) recombine into products (cake)

        dissolution: into ions  ex:  .  water is solvent

        oxidation: ex:   O steals e- from Fe

        combustion:  ex: 

       acid-base:  ex:

 

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