now a node can be further classified as either a radial note or angular note. Now a radio note is just the spiritual region that separates the different shells. Here we have Shell one, which is n equals one shell to which is an equals two and then shell three. The space between them are your radio nose, and the number of radio nose is equal to N minus your annual mentum quantum number L plus one. Your angular node is are basically flat cones or planes that dissecting orbital's oven Adam. So this is more three dimensional. Basically, what you need to know here is that the number of angular nodes is equal to just L, which is your angular momentum quantum number. So we now know how to calculate the total number of note by N minus one. Those total number of nodes could be further separated into either radio notes or angular nodes. Here we have their formulas and purple boxes, which means it's up to you to memorize them.