Your Name:
Date:
Class:

Homework: Atomic Structure II

  1. Define the following key terms:
    1. energy level
    2. filled shell
    3. valence shell
    1. covalent bond
    2. minimize energy
    3. overall charge
  2. Define a cation. How does an atom become a cation?
  3. Under what circumstances does an atom become a cation? Why would it do so?
  4. Define an anion. How does an atom become an anion?
  5. Under what circumstances does an atom become an anion? Why would it do so?
  6. How does the formation of a covalent bond help an atom to fill its valence shell?
  7. Fill in the blanks in the following table, paying special attention to atomic charge.
    Name Symbol No. of p+ No. of n0 No. of e Overall
    Charge
    iron-54 5426Fe2+        
        5 6 5  
          16 18 –3
        79 118 78  
    barium-137     81   +2
  8. One isotope of a metallic element has mass number 65 and 35 neutrons in its nucleus. The cation derived from the isotope has 28 electrons. Write the symbol for this cation.
  9. One isotope of an alkali metal has mass number 87 and 50 neutrons in its nucleus. The cation derived from the isotope has 36 electrons. Write the symbol for this cation.
  10. One isotope of a non-metallic element has mass number 81 and 46 neutrons in its nucleus. The anion derived from the isotope has 36 electrons. Write the symbol for this anion.



page break
 
  1. What is a Group in the periodic table? What do you know about the valence electrons of the elements in a group?
  2. The elements in a group have similar chemical and physical properties. Remember the video you watched in class about how the alkali metals (Li, Na, K, Rb, and Cs) react when exposed to water. Using what you know about the valence electrons of elements in a group explain why elements in a group have similar properties.
  3. What is another name for an electron shell? (Look back at the text of the group activity or at your notes).
  4. What is the reason electrons only exist in shells and never between them? Think about quantum energy.
  5. Why do atoms try to have filled shells?
  6. What is the difference in terms of chemical reactivity between an atom with an unfilled valence shell and one will a filled valence shell?
  7. What is more reactive, a fluoride ion (F) with a full valence shell or a fluorine atom (F) with only seven valence electrons? Why?
  8. Based on your knowledge of groups in the periodic table, predict the likely charges of the following atoms if they were to form ions by gaining or losing electrons to fill their valence shell:
    Ca                        Li                        Cl                       N                          Ne                        Mg                        Si
    
    Ba                        Rb                        I                        As                        Xe                        Sr                        Pb
    
    

    Show the charge of each atom by writing it as a superscript next to the symbol. Underneath each symbol write how many e- are gained or lost.
  9. Draw the Lewis electron dot structure of the electrically neurtral atoms from the previous problem.
  10. If you draw the Lewis electron dot structure for ions they would all look the same. Why? Think about how many valence electrons an ion has.
Students will need a periodic table to complete this exercise.
This homework belongs with the Atomic Structure II Group Activity.
Last updated: Feb 04, 2013       Home