Which orbital has no node?
Group of answer choices 1s 2s 2p 3d 4f
The correct answer and explanation is:
The correct answer is 1s.
The 1s orbital has no nodes. In atomic orbitals, nodes refer to regions where the probability of finding an electron is zero. These nodes occur at certain distances from the nucleus where the wavefunction of the electron passes through zero. The number of nodes increases with the principal quantum number (n) and the orbital type (s, p, d, f).
For the 1s orbital, the quantum numbers are:
- n = 1 (principal quantum number)
- l = 0 (azimuthal quantum number for s orbitals)
An s orbital has spherical symmetry, and the probability distribution of the electron is highest at the nucleus and decreases as you move away from it. Since the 1s orbital corresponds to the lowest energy level, it does not have any nodes.
In contrast:
- The 2s orbital has one node.
- The 2p orbital has one angular node.
- The 3d orbital has two nodes.
- The 4f orbital has three nodes.
As the energy level (n) and angular momentum quantum number (l) increase, the number of nodes increases as well. Nodes are created where the wavefunction of the electron crosses zero, representing regions where there is no probability of finding the electron.
Therefore, the 1s orbital, being the simplest and lowest-energy orbital, has no nodes.