PYQ NEET- Structure Of Atom L-7

Question: $4 d, 5 p, 5 f$ and $6 p$ orbitals are arranged in the order of decreasing energy. The correct option is :#

A) $6 p>5 f>4 d>5 p$

B) $5 f>6 p>4 d>5 p$

C) $5 f>6 p>5 p>4 d$

D) $6 p>5 f>5 p>4 d$

Answer: $5 f>6 p>5 p>4 d$#

Solution:#

As per Aufbau principle $(n+I$ rule), higher is the value of $(n+l)$, greater will be the energy. When $(n+l)$ values are same then which orbital have higher value of $n$ will have more energy. $$ \begin{aligned} & 4 d=4+2=6 \ & 5 p=5+1=6 \ & 5 f=5+3=8 \ & 6 p=6+1=7 \end{aligned} $$

Hence, the correct order of decreasing energy will be : $5 f>6 p>5 p>4 d$.