JEE Main · 2021 · 25 Feb 2021 · Shift 1 · Atomic Structure

The Plots of radial distribution functions for various orbitals of hydrogen atom against '

r

' are given below:

(a) (see plot)
(b) (see plot)
(c) (see plot)
(d) (see plot)

The correct plot for 3s orbital is:

(A)(d)✓ Correct
(B)(b)
(C)(a)
(D)(c)

Answer: (A)

Solution

A radial distribution curve for an orbital with quantum numbers

n

and

ℓ

touches zero at

n - ℓ - 1

radial nodes and so rises to

n - ℓ

maxima. For a 3s orbital

n = 3

and

ℓ = 0

, giving two radial nodes and three maxima, with the outermost maximum much the largest and standing farthest from the nucleus. The curve with two small inner humps followed by a dominant peak near 7 angstrom is plot (d).

JEE Main · 2021 · 25 Feb 2021 · Shift 1 · Single correct option

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