1. Which of the following statements are true? (Select all that apply.)
A) An orbital of principal quantum number n has n –1 nodes.
B) The value of ℓ gives the number of planar (angular) nodes.
2. How many nodes of all types does a 3d orbital have?
1 Answer

Q1)
A: TRUE
The total number of nodes for a given principal quantum number n is (n1).
B: TRUE
The number of angular nodes is given by the orbital quantum number ℓ.
Note that:
ℓ=0 is sorbital
ℓ=1 is porbital
ℓ=2 is dorbital
ℓ=3 is forbital
Examples:
For sorbitals, ℓ=0, thus they have ZERO angular nodes (Testifies B)
1s orbital has ZERO nodes (Testifies A, since n1 = 1 – 1 = 0 total)
2s orbital has ONE radial node (Testifies A, since n1 = 2 – 1 = 1 total)
3s orbital has TWO radial nodes (Testifies A, since n1 = 3 – 1 = 2 total)
4s orbital has THREE radial nodes (Testifies A, since n1 = 4 – 1 = 3 total)
For porbitals, ℓ=1, thus they have ONE angular node (Testifies B)
2p orbital has ONE angular node + ZERO radial node (Testifies A, since n1 = 2 – 1 = 1 total)
3p orbital has ONE angular node + ONE radial node (Testifies A, since n1 = 3 – 1 = 2 total)
4p orbital has ONE angular node + TWO radial node (Testifies A, since n1 = 4 – 1 = 3 total)
For dorbitals, ℓ=2, thus they have TWO angular node (Testifies B)
3d orbital has TWO angular node + ZERO radial node (Testifies A, since n1 = 3 – 1 = 2 total)
4d orbital has TWO angular node + ONE radial node (Testifies A, since n1 = 4 – 1 = 3 total)
For forbitals, ℓ=3, thus they have THREE angular node (Testifies B)
4f orbital has THREE angular node + ZERO radial node (Testifies A, since n1 = 4 – 1 = 3 total)
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Q2) From the examples above, we can see that:
3d orbital has TWO angular node + ZERO radial node
Source(s): I teach chemistry