Question

Assertion(A):For the outermost electron in Na atom, the orbital angula r momentum is
zero.
Reason(R): For 3s electron, l=0 and orbital angular momentum is zero.


(i) Both assertion and reason are correct statements, and reason is the correct explanation of the
assertion.
(ii) Both assertion and reason are correct statements, but reason is not the correct explanation of
the assertion.
(iii) Assertion is correct, but reason is wrong statement.
(iv) Assertion is wrong but reason is correct statement.
(v) Both assertion and reason are wrong statements.

Answer 1

Electron configuration of Na :

$\dag\:\underline{\boxed{\bf{\gray{_{11}Na^{23}=1s^2\:2s^2\:2p^6\:3s^1}}}}$

• Atomic number = 11

❖ Orbital angular momentum of electron is given by,

$\bigstar\:\underline{\boxed{\bf{\pink{OAM=\sqrt{l(l+1)}\:\dfrac{h}{2\pi}}}}}$

where,

l denotes azimuthal quantum number

❖ Azimuthal quantum number 'l' is also known as subsidiary quantum number which defines three dimensional shape of the orbital.

For a given value of n, l = 0 to n - 1

• for s orbital → l = 0
• for p orbital → l = 1
• for d orbital → l = 2
• for f orbital → l = 3

$\sf:\implies\:OAM=\sqrt{l(l+1)}\:\dfrac{h}{2\pi}$

$\sf:\implies\:OAM=\sqrt{0(0+1)}\:\dfrac{h}{2\pi}$

$\bf:\implies\:OAM=0$

• For the outermost electron in Na atom, the orbital angular momentum is zero it is because for electron of 3s orbital, l is taken 0.

∴ Both assertion and reason are correct statements, and reason is the correct explanation of the assertion (A).

Answer 2

Answer:

(A) Both assertion and reason are correct