Borazine \(\left(\mathrm{B}_{3} \mathrm{~N}_{3} \mathrm{H}_{6}\right)\) has often been called "inorganic" benzene. Write Lewis structures for borazine. Borazine contains a sixmembered ring of alternating boron and nitrogen atoms with one hydrogen bonded to each boron and nitrogen.

First, we need to find the total number of valence electrons in a molecule of borazine. This can be done by looking at the periodic table and counting the valence electrons for each atom present in the molecule. - Boron (B) has 3 valence electrons. - Nitrogen (N) has 5 valence electrons. - Hydrogen (H) has 1 valence electron. Since borazine has 3 boron atoms, 3 nitrogen atoms, and 6 hydrogen atoms, the total number of valence electrons in the molecule is: (3 × 3) + (3 × 5) + (6 × 1) = 9 + 15 + 6 = 30 valence electrons.

Let's draw the skeletal structure of borazine with alternating boron and nitrogen atoms in the six-membered ring with one hydrogen bonded to each boron and nitrogen atom: ``` H H | | B-N-B-N-B-N | | H H ```

Now, distribute the remaining valence electrons as lone pairs around each atom to complete the octet rule for nitrogen atoms (8 electrons), and satisfy the electron requirements for boron atoms (6 electrons) and hydrogen atoms (2 electrons). Recall that the total number of valence electrons is 30. We have already used 12 electrons to create the covalent bonds between B-N, N-H, and H-B. This leaves us with (30 - 12) = 18 valence electrons to distribute as lone pairs. The boron (B) atoms can accommodate up to 6 electrons each. Since each boron atom is sharing 2 electrons with its two neighboring nitrogen atoms, and 2 electrons with one hydrogen atom, no more electrons need to be added. For nitrogen (N) atoms, each needs to follow the octet rule, meaning they should have 8 electrons within their valence shell. At the moment, each nitrogen atom is sharing 2 electrons with each of its neighboring boron atoms and 2 electrons with one hydrogen atom. So, there are a total of 6 electrons around each nitrogen atom. To complete the octet rule, we'll add a lone pair (2 electrons) to each nitrogen atom. The hydrogen (H) atoms already satisfy the duet rule and no more electrons need to be added.

After assigning all valence electrons as lone pairs or covalent bonds, we can draw the completed Lewis structure of borazine: ``` H H | | B-N-B-N-B-N | ¦ | ¦ H H ``` In this structure, the boron and nitrogen atoms form a six-membered ring with single covalent bonds between them. Each nitrogen atom has a lone pair, and each boron and nitrogen atom is bonded to one hydrogen atom.