Cl Cl Br Br I I #7 Draw electron dot structures for each molecule UNSHARED PAIRS First step is to place the correct number of valence electrons on the drawing. a. chlorine Cl Cl Chlorine shares two electrons with another chlorine. Second step is to show sharing of electrons. b. bromine Br Br I I c. iodine a diatomic molecule; Br2 I2 Cl2 etc.

a. H2O2 b. PCl3 #8 The following molecules have single covalent bonds. Draw an electron dot structure for each. a. H2O2 H O O H Cl b. PCl3 P Cl Cl

#9 Draw the electron dot structure of the hydroxide ion OH- -1 O H Note that the hydroxide ion has one extra electron than the total you expect form oxygen and hydrogen alone (6+1=7). Electron #8 came from another atom that donated it to the hydroxide ion.

#10 Draw the electron structure of the polyatomic boron tetrafluoride anion (BF4-1) F F B F F notice that one extra electron (shown as the yellow on in this picture) is needed to complete the molecule. That is why BF4 has a negative one charge. 3D view of BF4

#11 Draw the electron dot structures for sulfate (SO4)-2 and carbonate (CO3)-2. Sulfur and Carbon are the central atoms, respectively. O 1. put in the valence electrons that each atom has, be sure to add two extra electrons (yellow) due to the negative 2 charge on this molecule. S O O O sulfate (SO4) -2

DONE! O S O O O sulfate (SO4) -2 #11 Draw the electron dot structures for sulfate (SO4)-2 and carbonate (CO3)-2. Sulfur and Carbon are the central atoms, respectively. O 2. arrange the electrons so as to best fulfill the octet rule. S O O DONE! O sulfate (SO4) -2

#11 Draw the electron dot structures for sulfate (SO4)-2 and carbonate (CO3)-2. Sulfur and Carbon are the central atoms, respectively. O 1. put in the valence electrons that each atom has, be sure to add two extra electrons (yellow) due to the negative 2 charge on this molecule. C O O carbonate (CO3) -2

DONE! O C O O carbonate (CO3) -2 #11 Draw the electron dot structures for sulfate (SO4)-2 and carbonate (CO3)-2. Sulfur and Carbon are the central atoms, respectively. O 2. arrange the electrons so as to best fulfill the octet rule. C O O DONE! carbonate (CO3) -2

O C O O H #12 Draw the electron dot structure for the hydrogen carbonate ion (HCO3)-1 Carbon is the center atom, and hydrogen is attached to oxygen in this polyatomic anion. O 1. put in the valence electrons that each atom has, be sure to add one extra electron (yellow) due to the negative 1 charge on this molecule. C O O H

DONE! O C O O H hydrogen carbonate (HCO3) -1 #12 Draw the electron dot structure for the hydrogen carbonate ion (HCO3)-1 Carbon is the center atom, and hydrogen is attached to oxygen in this polyatomic anion. 2. arrange the electrons so as to best fulfill the octet rule. O C O O DONE! H hydrogen carbonate (HCO3) -1