Assertion : $^{'} L a^{'}$ should be the $f$ -block element according to Aufbau principle. Reason: $57 t h$ electron exceptionally enters into the $5 d$ -orbital.

Read the above assertion and reason and choose the correct option regarding it.

Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Assertion is correct but Reason is incorrect

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Assertion is incorrect but Reason are incorrect

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
The outermost configuration led to putting the La in the d-block elements and not f-block and all lanthenides are following the general configuration: [Xe] $6 s^{2} 5 d^{1}, 4 f^{1 - 14}$ . It is an exception of Aufbau's rule.

Suggest Corrections

Similar questions

H_{2}

H e

(1 + \frac{P b}{R T})

H_{2}

H e

Assertion: All the points (1, 0), (-1, 0), (2, 0) and (5, 0) lie on the x – axis.

Reason: Equation of the x – axis is y = 0
Now, choose the correct option.

L a

Assertion – The non-fusible impurities present in iron ore are removed by $C a C O_{3}$ .

Reason: $C a C O_{3}$ which decomposes into $C a O$ and $C O_{2}$ . The $C a O$ formed reacts with $S i O_{2}$ to remove silica

{2n}^{2}

Join BYJU'S Learning Program