The number of radial nodes, nodal planes for an orbital with n = 4; l = 1 is;

To find the number of radial nodes and angular (nodal plane) nodes for an atomic orbital we use the quantum numbers given:

$n=4, l=1$

The total number of nodes in an orbital is the principal quantum number minus one:

$n-1$

These nodes are split into radial nodes and angular nodes. The radial nodes are given by the formula

$R=n-l-1$

Substituting the values:

$R=4-1-1=2$

Thus the orbital has **2 radial nodes**.

The angular nodes are directly equal to the azimuthal quantum number:

$A=l$

So

$A=1$

This means there is **1 nodal plane** (angular node).

Therefore, for an orbital with $n=4$ and $l=1$, the numbers are:

$2, 1$

i.e., 2 radial nodes and 1 nodal plane.