Orbitals are region or space where there is maximum probability of finding electrons. Qualitatively, these orbitals can be distinguished by their size, shape and orientation. An orbital of small size means there is more chance of finding the electron near the nucleus. Shape and orientation mean the direction in which probability of finding electron is maximum. Atomic orbitals can be distinguished by quantum numbers. Each orbital is designated by three quantum numbers n, l and ml (magnetic quantum number) which define energy, shape and orientation but these are not sufficient to explain spectra of multi-electrons atoms. Spin quantum number (ms) determines the spin of electron. Spin angular momentum of electron has two orientations relative to chosen axis which are distinguished by spin quantum numbers ms which can take values +1/2 and –1/2.

Concept of Atomic Orbital, Quantum Numbers and Their Significance, Electron Spin and Spin Quantum Number

Concept of Atomic Orbital, Quantum Numbers and Their Significance, Electron Spin and Spin Quantum Number | PadhAiPro