10.1d Identification of primary, secondary and tertiary carbon atom

What decides whether a carbon is primary (1), secondary (2), or tertiary (3)?

Answer: the number of carbon(s) that the carbon that is connected to the functional group is connected to.

What!??!! Look at the examples below. The functional group is -OH, what's the difference among them?

Why should this matter?

Answer: Primary and secondary alcohols can oxidized (later topic), tertiary alcohols cannot. Thus you can distinguish them using an oxidizing agent like acidified dichromate (H⁺/Cr₂O₇^2-)