The Probability Density of a Particle at a Distance R $\int _ { 0 } ^ { 2 } \Psi ^ { 2 } 4 \pi r ^ { 2 } d r$

Multiple Choice

The probability density of a particle at a distance r from the nucleus is essentially the

A) probability of finding the particle within a small volume about r.
B) probability per unit area of finding the particle within a unit area centered on r.
C) probability per unit length of finding the particle within a unit length of r.
D) probability per unit volume of finding the particle within a small volume about r.
E) $\int _ { 0 } ^ { 2 } \Psi ^ { 2 } 4 \pi r ^ { 2 } d r$