Draw a Lewis dot symbol for atoms of arsenic (As).

Identify the group of the periodic table in which the element with the following Lewis symbol belongs:

Provide a Lewis dot symbol for each of the ions in Na₂O.

Identify the bond between each pair as ionic or covalent.

i) P and O
ii) Ba and S
iii) N and Br
iv) Cr and O

Identify the compound that has bonds with the least covalent character.

Determine if P₈, MgCl₂, POCl₃, NaF, CBr₄, BrF, KCl, NH₃ have polar, nonpolar covalent, or ionic bonds.

Rank in decreasing magnitude of dipole moment and determine the direction of the bond dipoles: H₂Se, H₂O, and H₂S.

List the following bonds from most to least polar:

 S-F, N-Cl, Si-O

The octet rule applies to the elements of the main group but not to transition metals. Explain.

The octet rule is often disobeyed by elements in the 3rd row and beyond of the periodic table. Which of the following statement explains this? 

Which of the atoms below can expand its valence shell when bonding?