How many nodes would you expect in the 4s radial probability function?

In a 4s radial probability function, there are two types of nodes: angular nodes and radial nodes. The 4s orbital has 0 angular nodes and (n - 1 = 3) total nodes, where (n) is the principal quantum number (4 in this case). Since all nodes must be radial for an s orbital, the 4s radial probability function would have 3 radial nodes.