Question

33. Explain briefly why each of the following is not a pos- 6 nm. adia- sible set of quantum numbers for an electron in an atom. (a) n = 2, 1-2,m = 0 (c) n 6, -0, m 1

Answer 1

To define an electron in an atom, it must need to define all the quantum numbers. n is principle quantum number, it is the shell of an atom, starts from 1, 2, 3 ......n, represents as K, L, M, ...... and l is the subshell of an atom, starts from 0, 1, 2, ............ n-1 and represent as s, p, d,.......... and m_l should have ......+2,+1, 0, -1, -2, ......

Thus for (a) n = 2, l must have s and p subshell and not d subshell and m_l values must be 0 and +1, 0, -1

(b) for n = 3, l must have s, p and d subshell and m_I must be 0 (for s), +1, 0 -1, (for p) and -2, -1, 0 +1, 2 (for d).

(c) for n = 6, l must have s, p, d, f, g, h subshell and m_I must be 0 (for s), +1, 0 -1, (for p) and -2, -1, 0 +1, 2 (for d) and so on.