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Chemistry LibreTexts

Answers to Chapter 02 Study Questions

    1. law of multiple proportions
    2. law of conservation of mass
    3. law of definite proportion
       
  1. Rutherford’s experiment supported the ideas that atoms contain a small dense center (nucleus) and are mostly empty space.
     
  2.  
Nuclear Symbol Atomic Number Mass Number Number of Protons Number of Electrons Number of Neutrons Charge
\(\mathrm{^{40}_{18}Ar}\) 18 40 18 18 22 0
\(\mathrm{^{39}_{19}K^+}\) 19 39 19 18 20 +1
\(\mathrm{^{36}_{16}S^{2-}}\) 16 36 16 18 20 -2

 

  1. \(\mathrm{^{20}_{10}Ne}\) and \(\mathrm{^{22}_{10}Ne}\)
     
    1. MG, Group 2, metal, Period 5
    2. MG, Group 17, nonmetal, Period 4
    3. TM, Period 5
    4. MG, Group 15, nonmetal, Period 3
    5. MG, Group 13, metalloid, Period 2
    6. ITM, Period 7
    7. MG, Group 14, metal, Period 5
    8. TM, Period 6
       
  2. Group 1 = alkali metals; Group 2 = alkaline earth metals; Group 17 = halogens; Group 18 = noble gases.
     
  3. Elements:  \(\ce{O2}\), \(\ce{N2}\), \(\ce{Cl2}\), or any other diatomic element.  Compounds:  \(\ce{CO2}\), \(\ce{H2O}\), \(\ce{NH3}\), or any other covalent compound.
     
    1. positive, +1
    2. positive, +2
    3. negative, -1
    4. negative, -2
    5. positive, +1
       
    1. covalent, dinitrogen oxide or dinitrogen monoxide    
    2. ionic, potassium oxide
    3. covalent, phosphorus trichloride                                 
    4. ionic, aluminum phosphate
    5. covalent, hydrochloric acid                                         
    6. ionic, ammonium fluoride
    7. ionic, lead(II) nitrite                                                   
    8. covalent, sulfurous acid
       
    1. calcium carbonate                  
    2. zinc sulfide                       
    3. copper(I) hydroxide
    4. magnesium perchlorate
       
    1. \(\ce{K3PO4}\)
    2. \(\ce{(NH4)2SO4}\)       
    3. \(\ce{Co(OH)2}\)
    4. \(\ce{FeN}\)
       
    1. \(\ce{PI3}\)
    2. \(\ce{N2O5}\)            
    3. \(\ce{HClO3}\)