with quantum mechanics were obsessed with finding the location of an electron. But just remember that a vast majority of the atom itself is empty space. Since the electrons are so small, we're gonna say a node is the region within an atom where the probability of finding an electron is zero. We need to say that this region has zero electron density. We're gonna say electron shell is the region where electrons reside with highest probability, which is what we've been focusing on in terms of quantum mechanics. Now to determine the total number of nodes, just remember that it's equal to your principal quantum number. N minus. What? So if you know your principal quantum number for a given set of orbital's so tracked one and that be equal to the number of notes