Mr. Balmer              Name:              
       
                  Periodic Variation in Properties (30pts) 
                           
      Purpose:  It is your group’s job to make a line graph comparing your assigned property to the 
      atomic number of the first 20 elements. 
       
      Materials:  calculator, element data cards, graph paper, ruler, Microsoft Excel 
       
      Prelab Questions:  Define the following terms.  (5pts) 
       
      1) Density: 
       
       
      2) Melting Point: 
       
       
      3) Electrical Conductivity: 
       
       
      4) Atomic radius: 
       
       
      5) Electronegativity: 
       
       
      6) First Ionization Energy: 
                                              
       
      Procedure: Make a line graph according to your group’s data listed below. (10pts) 
       
      Group 1— Make a line graph comparing density and atomic number 
       
      Group 2— Make a line graph comparing melting point (in ºC) and atomic number.      
       
      Group 3—Make a line graph comparing electrical conductivity and atomic number.   
       
      Group 4—Make a line graph comparing atomic radius (in nm) and atomic number.   
       
      Group 5—Make a line graph comparing electronegativity (Pauling’s) and atomic number.  
       
      Group 6—Make a line graph comparing the first ionization energy and atomic number.   
                                              
       
      Questions:  Use complete sentences for full credit.  (10pts) 
       
        1.  Does your graph reveal a repeating, or cyclic, pattern?  (Hint:  Focus on the highs and 
         lows of your graph.)  Describe any patterns you observe. 
         
         
         
         
         
       
         
        2.  Cut out your element cards and arrange them in a row.  When the pattern you observed in 
         your graph repeats, start a new row below the first row.  Draw a picture of your 
         arrangement below.  Do you notice anything special about your arrangement?   
        Ex)  A  B  C  D  E 
          F  G  H   I   J 
          K  L  M  N  O 
         
         
         
         
         
        3.  Where are elements with the highest densities located on the Periodic Table? 
         
         
         
         
       
        4.  Where are elements with the highest melting points located on the Periodic Table? 
         
         
         
         
       
         
       
        5.  Where are elements with the highest electrical conductivity located on the Periodic 
         Table? 
       
       
       
       
       
       
       
       
        6.  Where are elements with the largest atomic radius located on the Periodic Table? 
         
         
         
         
       
       
       
       
        7.  Where are elements with the highest electronegativity located on the Periodic Table? 
         
         
       
       
        8.  Where are elements with the highest ionization energy located on the Periodic Table? 
         
         
         
         
         
         
         
        9.  Based on your graphs and the Periodic Table, predict what properties the following 
         elements might have.  Explain Your Answers.   
         
        A) rubidium (Rb)—  
         
         
         
         
         
         
         
        B) bromine (Br)—         
         
         
         
         
         
         
       
        10. Based on the class’s graphs, why is the chemist’s organization of elements called a 
         periodic table? 
         
         
         
         
         
                                              
         
      Conclusion- 5-6 sentences (5pts) 
                   H- Hydrogen                         C- Carbon (diamond) 
                 Atomic Number: 1                       Atomic Number: 6 
         Density: 0.0000899 g/mL (H  gas)               Density: 3.51 g/mL 
                                    2
         Melting Point: -259.34 ºC (H  gas)     Melting Point: -- ºC (enter 3000ºC) 
                                    2
                           7            -1                         7           -1
          Conductivity (x 10 ): 0.00 (Ωm)        Conductivity (x 10 ): 0.00 (Ωm)  
              Atomic Radius: 0.079 nm                Atomic Radius: 0.091 nm 
               Electronegativity: 2.10                Electronegativity: 2.55
                                                                            
          st                                     st
        1  Ionization Energy: 1312.0 kJ/mol     1  Ionization Energy: 1086.4 kJ/mol 
                    He- Helium                             N- Nitrogen 
                 Atomic Number: 2                       Atomic Number: 7 
              Density: 0.0001785g/mL              Density: 0.00125g/mL (N  gas) 
                                                                          2
              Melting Point: -272.2 ºC          Melting Point: -209.86 ºC (N  gas) 
                                                                            2
                           7            -1                         7           -1
          Conductivity (x 10 ): 0.00 (Ωm)        Conductivity (x 10 ): 0.00 (Ωm)  
             Atomic Radius: 0.049 nm                 Atomic Radius: 0.075 nm 
               Electronegativity: 0.00                Electronegativity: 3.04
                                                                            
          st                                     st
        1  Ionization Energy: 2372.2 kJ/mol     1  Ionization Energy: 1402.3 kJ/mol
                                                                                   
                    Li- Lithium                            O- Oxygen 
                 Atomic Number: 3                       Atomic Number: 8 
                Density: 0.534g/mL               Density: 0.001429 g/mL (O  gas) 
                                                                           2
              Melting Point: 180.54 ºC           Melting Point: -218.4 ºC (O  gas) 
                                                                           2
                           7            -1                         7           -1
          Conductivity (x 10 ): 1.17 (Ωm)        Conductivity (x 10 ): 0.00 (Ωm)  
             Atomic Radius: 0.205 nm                 Atomic Radius: 0.065 nm 
               Electronegativity: 0.98                Electronegativity: 3.44
                                                                            
          st                                     st
         1  Ionization Energy: 520.2 kJ/mol     1  Ionization Energy: 1313.9 kJ/mol 
                   Be- Beryllium                           F- Fluorine 
                 Atomic Number: 4                       Atomic Number: 9 
                 Density: 1.85g/mL                    Density: 0.00169 g/mL  
               Melting Point: 1278 ºC                Melting Point: -219.62 ºC  
                           7            -1                         7           -1
          Conductivity (x 10 ): 2.50 (Ωm)        Conductivity (x 10 ): 0.00 (Ωm)  
             Atomic Radius: 0.140 nm                 Atomic Radius: 0.057 nm 
               Electronegativity: 1.57                Electronegativity: 3.98
                                                                            
          st                                     st
         1  Ionization Energy: 899.4 kJ/mol     1  Ionization Energy: 1680.9 kJ/mol 
                     B- Boron                               Ne- Neon 
                 Atomic Number: 5                      Atomic Number: 10 
                Density: 2.34 g/mL                   Density: 0.000900 g/mL  
               Melting Point: 2300 ºC                Melting Point: -248.67 ºC  
                           7            -1                         7           -1
          Conductivity (x 10 ): 0.00 (Ωm)        Conductivity (x 10 ): 0.00 (Ωm)  
             Atomic Radius: 0.117 nm                 Atomic Radius: 0.051 nm 
               Electronegativity: 2.04                Electronegativity: 0.00
                                                                            
          st                                     st
         1  Ionization Energy: 800.6 kJ/mol     1  Ionization Energy: 2080.6 kJ/mol