Question

The correct order of penetration power of the orbitals is

• A. \(4s < 4p < 4d < 4f\)
• B. \(4s > 4p > 4d > 4f\)
• C. \(4s > 4d > 4p > 4f\)
• D. \(4s < 4p < 4f < 4d\)

Hint:

For orbitals of the same shell, penetration order always follows: \[ s > p > d > f \]

Answer 1

The Correct Option is B

Concept:
Penetration power refers to the ability of an electron in an orbital to move closer to the nucleus. Greater penetration means:
• stronger attraction toward nucleus,
• lower energy,
• greater stability. Among orbitals of the same principal quantum number, penetration power decreases in the order: \[ s > p > d > f \]

Step 1: Understanding orbital penetration.
Electrons in \(s\)-orbitals spend more time near the nucleus compared to \(p\), \(d\), and \(f\) orbitals. Therefore: \[ s\text{-orbital has maximum penetration} \] Similarly: \[ p > d > f \]

Step 2: Applying the rule to \(n=4\) orbitals.
For orbitals: \[ 4s,\ 4p,\ 4d,\ 4f \] the penetration order becomes: \[ 4s > 4p > 4d > 4f \] Thus, the correct option is: \[ \boxed{(2)\ 4s > 4p > 4d > 4f} \]