Sulfur forms covalent bonds with chlorine and carbon, but forms ionic bonds with calcium and lithium. What is the BEST description for this difference in how oxygen behaves?
A. Sulfur bonds randomly with elements in unpredictable ways
B. Sulfur bonds with elements that have a smaller atomic mass
C. Electronegativity differences between bonding elements allow electrons to be either shared or donated
D. The difference in atomic radii between the groups accounts for the difference in behavior