Today’s post covers two lessons of material: tricks for drawing compounds, and polyatomic ions.
Most periods tackled drawing compounds today. We learned that finding the central atom in a salt is different from finding it in a molecule. For salts, the atom with the lowest number/highest charge is the central atom. Some periods also covered the last trick for bonding: when we are missing hydrogens, we have a double bond, triple bond, or the molecule is a circle.
For the periods that are a little farther ahead, we covered polyatomic ions. Polyatomic means “many atom.” Essentially, it is possible to have a molecule serve as a cation or anion in a salt. We treat these polyatomic ions like inseparable units: we don’t worry about our NO3- breaking down, we just use it as an ion that can cancel one positive charge.