Question

Which of the given statement (s) is/are false.

I Orbital angular momentum of the electron having n = 5 and having value of the azimuthal quantum number as lowest for this principle quantum number is .

II If n = 3, l = 0, m = 0, for the last valence shell electron, then the possible atomic number must be 12 or 13.

III Total spin of electrons for the atom 25Mn is ± .

IV Spin magnetic moment of inert gas is 0

• A. I, II and III
• B. II and III only
• C. I and IV only
• D. None of these

Answer 1

Answer: (A)

I, II and III

Answer 2

I : For n = 5, lmin = 0. $\therefore$ Orbital angular momentum $= \sqrt{\mathcal{l}\left( \mathcal{l} + 1 \right)}\hslash = 0.$ (False)

II : Outermost electronic configuration = 3s1 or 3s2.

$\therefore$ possible atomic number = 11or 12 (False).

III : Mn25 = [Ar] 3d5 4s2.

$\therefore$ 5 unpaired electrons.

$\therefore$Total spin $= \pm \frac{5}{2}$ (False).

IV : Inert gases have no unpaired electrons.

$\therefore$spin magnetic moment = 0 (True)