Question
Chemistry Question on p -Block Elements
How many of the following have five radial nodes?
5s, 6s, 7s, 6p and 4p
Answer
The number of radial nodes for an electron in an orbital is given by n - l - 1, where n is the principal quantum number and l is the azimuthal quantum number.
For an s orbital, l = 0, so the number of radial nodes is n - 1. For a p orbital, l = 1, so the number of radial nodes is n - 2.
Therefore, the number of radial nodes for each of the orbitals are:
5s: 5 - 1 - 0 = 4 radial nodes
6s: 6 - 1 - 0 = 5 radial nodes
7s: 7 - 1 - 0 = 6 radial nodes
6p: 6 - 2 - 1 = 3 radial nodes
4p: 4 - 2 - 1 = 1 radial node
Only the 6s orbital has five radial nodes. Therefore, only one of the given orbitals has five radial nodes.
Answer. 6s