ELEMENTS _ ATOMS

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ELEMENTS _ ATOMS Powered By Docstoc
					Name:___________________________________Period:_______Date:__________
I. ELEMENTS & ATOMS:
   ______________= A substance that cannot be broken down into simpler substances
         o Periodic Table
               1-92 occur in ___________(natural elements)
               93 and above are ___________(man-made)
       Natural Elements:
         o _____are essential to living things
         o Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N) make up 96% of human
           mass
       Trace Elements:
              o Found in very_________ amounts but are __________to proper
                 cellular activities
              o Ex: iron, magnesium, iodine

   ______= Smallest particle of an element that has the characteristics of that element
         o 3 Subatomic particles make up an atom:
                1. ___________(P) = __________charged particles
                2. __________ (N) = no charge (__________)
                3. _____________(e-) = (____________charge) move nearly the speed
                   of light form a cloud around the nucleus

                      Nitrogen Atom




          o 2 parts of an atom:
                1. _________= Center of atom; contains __________& ____________
                2. ___________________________– around the nucleus



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II. ISOTPES:
    _____________= Atoms of the same element that have different numbers of
     ___________
           o Named by their ______________
                    C-12 = ( _______+ 6 P)
                    C-13 = ( ______+ 6 P)
                    C-14= ( _____+ 6 P)  Radioactive (nuclei break apart)
                           Used in the medical field


III.ATOMIC NUMBER & ATOMIC MASS:
    _______________= number of ________and/or ___________of an atom
                    Ex: Na-23 contains 11 electrons and 11 protons
    ______________= the _____of protons and neutrons of an atom
           o _________________________________________________


IV.ENERGY LEVELS & DIAGRAMING ATOMS:
    ________________= regions around the ___________that electrons travel
           o 1st energy level can ONLY have ____electrons
                    Except Hydrogen; it has only 1 e-

           o ____________________= Each energy level AFTER the first can have up
             to ____electrons
                 (2n2)
                 So 3rd energy level has 18 e- (2 · 32) = 18
                
 DIAGRAMING ATOMS:
                                                                 Ex: Chlorine (Cl)
           Ex: Helium (He)                               Atomic # = 17; Mass # = 35
    Atomic # = 2; Mass # = 4




                                     Nucleus

                                                                                      2
                                Ex: Carbon (C)
                       Atomic # = 6; Mass # = 12




I. COMPOUNDS & BONDING:
    ________________= a substance made of chemically combined elements.
    Atoms bond to form _________________
        o Atoms need _____________in OUTER energy level to be stable;
                 Exception: hydrogen needs 2 e-
    Open bonding sites (electrons) encourage _____________
    Elements can combine in two ways:
     1. ____________________:
           o Covalent bonds _____________ electrons
                     The positively charged nucleus is _______________to the
                      negatively charged electrons
           o Water, sugars, fats, and proteins are ________________________
           o ________________= a group of covalently bonded atoms with ___charge
                     Ex: H2O  2 hydrogen atoms + 1 oxygen atom




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                           - Oxygen needs _______electrons to become stable

                           - Each hydrogen needs ____electron to fill orbital
                                  Therefore, they__________!!




2. ________________:
          o ______________of electrons creating ions that attract each
            other = _________
          o _________= charged atoms because they have _________or
            ________electron(s)
               o Atoms that _______electrons become more ___________
               o Atoms that ______electrons become more _____________
               o Atoms gain/lose electrons efficiently




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                                     Ionic Bonding


   Na (11)
                                                                                     Cl (17)
             +
        11                                                                                   +
                                                                                         17
                 -
       +11e                                                                                          -
                                                                                         +17e
         0
                                                                                             0



Na loses 1e-                                                              Cl gains 1e-
             +                                                                       +
        11                                                                          17
                 -                                                                       -
       +10e                                                                        +18e
   +                                                                           -
       1 ION                                                                       1 ION




                                                             Na+1 + Cl-1 --> NaCl




                                                             Na+1 + Cl-1  NaCl




             ~More effective to _____an electron than to ______an electron!!




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II. WATER IS POLAR
 o __________= unequal distribution of charge
 o Each molecule has a _____________end and a ____________end
                                   o Ex: Water (H2O) molecule --> Oxygen is
                                      much stronger and therefore has a stronger
                                      _________________than the hydrogen’s
                                      positive charge

                                      o Because of water’s polarity, it can
                                        _________many ionic compounds and other
                                        polar compounds such as _________

                                      o The water molecules also _________to
                                        each other because of___________
                                        (unequal distribution of charge)



 o The attraction of opposite charges forms a _____________bond called a
   ______________
      This keeps large molecules _____________(Ex: proteins)


III. UNIQUENESS OF WATER- due to its polarity!

   1. _______________________________________
         The polarity of water cause the surface layer of water molecules to act
           like a stretched film over the surface of the water (_______________)
               o Ex: water striders

   2. ________________________________________
         The polarity of water allows _____________to get water from
           the ____________
              o Water creeps up tubes in plant roots and stems


   3. _____________________________________
            Ice is _____________dense than water (ice floats!)




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I. CHEMICAL REACTIONS:
       All the chemical reactions in our bodies are called_______________________.
                 -    Breakdown and reassemble molecules in the body.
        Chemical reactions occur only when conditions are right:
                                Temperature
                                Availability of energy
                                Concentrations of compounds
                                pH of the environment
                                                How acidic/basic the environment is

II. WRITING A CHEMICAL EQUATION:

                             _________              _____          _________
                             _                      _              _

                                    CH4 + 2O2                 CO2 + 2H2O

                     (methane) + (oxygen)                      (carbon dioxide) + (water)

       ______________________= # of molecules of a compound
                            Ex: 6O2 = 6 molecules of Oxygen (O)
                                  3H2O =____molecules of H2O


       ___________________= # of atoms of an element
                            Ex: CH4 = 1 atom C, 4 atoms H
                                  CO2 = _____ atom of C, _____ atoms O


            How many atoms of O are in 6O2 ?
                                               _____atoms of O!

            The same number of atoms of elements are on the reactant and the product side of
             chemical equations because of the _____________________________________
             (atoms are never created or destroyed; they are simply rearranged!)….we must
             always balance equations using________________________!!
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III. pH, ACID, BASES:
   _____= how acidic or basic a substance is

   _________ = substance that forms H+ (hydrogen ions) in water
                H2O
      HCl                H+ + Cl-          (pH _________than 7)


   __________________= substance that forms OH- (hydroxide ions) in water
                  H2O
    NaOH                    Na+ + OH-      (pH ________ than 7)



   The pH scale:




             0                            7                             14



                       ______                            ______
                        ___                               ____




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