# What are orbital probability patterns?

Another term for "orbital probability pattern" is the orbital's radial density distribution. As an example, the following is the visual radial density distribution of the $1 s$ orbital:
...and the following graph describes the probability of an electron being found at a distance $r$ away from the center of the $1 s$ orbital, in x-axis units of ${a}_{0}$, where ${a}_{0} = 5.29177 \times {10}^{- 11} m$ is the Bohr radius:
The $1 s$ orbital's radial density distribution describes the probability density that you see as you start at the centerpoint of the orbital with a spherical viewing window of nothing, and start increasing the radius of that window (the x-axis value), plotting how often you see electrons as you do so. This "probability density" is the y-axis value.