Lowell High Chemistry – Lewis Dot Structures Worksheet

Lowell High School Chemistry                                                                                                                                                          

Lewis Dot Structures Practice Handout — due Wednesday, September 26, 2007                                                                                                                                                                                                                                                                     

Directions: Answer all questions on a separate sheet of paper. Staple this to your answer sheet.

[1] What is the difference between an anion and a cation?

[2] What is the difference between an ionic bond and a covalent bond?

[3] Define: valence electron, electron dot symbol.

[4] What is the octet rule? Explain its role in bonding between atoms.

[5] Explain why ionic compounds are electrically neutral.

[6] Draw the Lewis electron dot structures of the following atoms:

                  [a] Ca                     [b] K                       [c] Cl                      [d] Al                     [e] Kr                     [f] P

[7] Indicate how many electrons must be gained or lost by each of the following atoms to achieve a stable electron configuration, e.g. lose 3, gain 2, etc.? [Hint: Which group on the periodic table contains elements with a stable electron configuration?]

                  [a] Ca                     [b] K                       [c] Cl                      [d] Al                     [e] Kr                     [f] P

[8] Which of the following pairs of elements will or will not form ionic compounds? Explain why for each.

                  [a] sulfur and xenon

                  [b] sodium and calcium

                  [c] strontium and sulfur

                  [d] selenium and chlorine

 [9] Draw the Lewis dot structures of the following compounds:

[a] sodium chloride (NaCl)                                         

[b] hydrogen peroxide (H₂O₂)                                                                                         

[c] iodine gas (I₂)                                                                                   

[d] carbon tetrafluoride (CF₄)

[e] hexane (C₆H₁₄)

[f] hexene (C₆H₁₂)

[g] calcium sulfide (CaS)

[h] hydrogen cyanide (HCN)