Question 21
Which of the following statements concerning the quantum numbers are correct ?
(a) The angular momentum quantum number determines the three-dimensional shape of the orbital
(b) The principal quantum number determines the orientation and energy of the orbital
(c) Magnetic quantum number determines the size of the orbital.
(d). Spin quantum number of an electron determines the orientation of the spin of electron relative to the chosen axis.
Answer: (a) and (d).
(a) Azimuthal quantum number 'l' is also known as orbital angular momentum or subsidiary quantum number. It determines three dimensional shape of the orbital.
(b) The principal quantum number determines the size of the orbit.
(c) The magnetic quantum number determines the orientation of the electron cloud in a subshell
(d) An electron spins around its own axis, much in a similar way as the earth spins around its own axis while revolving around the sun. In other words, an electron has, besides charge and mass, intrinsic spin angular quantum number.