Finding Nodal Surfaces in Wave Function of H-Like Atom

[ritwik06]

Homework Statement

One wave function of H like atom is \psi=\frac{\sqrt{2}}{81\sqrt{\pi}a_{0}^{3/2}}(6-\frac{r}{a_{0}})\frac{r}{a_{0}}(e^{\frac{-r}{3a_{0}}})cos \theta

How many nodal surfaces are there?
1)1
2)2
3)3
4)none of these

The Attempt at a Solution

Its an objective question which I need to answer in less than a minute. Is it possible to do so?

The next thing that I assume i that the wave function is given in polar coordinate form, isn't it?? \psi=f(r,\theta, \phi)?
phi is absent what does it mean? I guess it means that its the p - orbital. then the anwer must be 2. Am I right?

Last but not the least. I am keen upon seeing the 3D picture this wave function generates. I have MATLAB but I don't know how to code in polar coordinate and all. Will somebody code this wave function for me which is compatible with MATLAB 2008?? Please. I shall be very grateful.
Thanks a lot.

 

[buffordboy23]

Isn't the number of nodal surfaces equal to the quantum number of your wave function?

 

[ritwik06]

Isn't the number of nodal surfaces equal to the quantum number of your wave function?

Thanks a lot but I know that already. Is it of any help with this particular problem?
And sir, can you please tell me how can I plot equations such as this one and like
x²+y²+z²=1 with MATLAB?

 

[buffordboy23]

Your given the wave function. The wave functions for the hydrogen atom are constructed from two separate functions, the spherical harmonic wave functions, Y^{m}_{l}\left(\theta,\phi\right), and the radial wave functions, R_{nl}\left(r\right):

\Psi_{nlm}\left(r,\theta,\phi\right) = R_{nl}\left(r\right)Y^{m}_{l}\left(\theta,\phi\right)

You really only need to look at the radial wave equation, since by definition it has a term e^{-r/na}, where n is the quantum number. So, this is easily determined by your given function.

I am pretty certain that n,l,m = 3,1,0 for your given wave function. Here's an applet to check out the probability density:

http://www.phy.davidson.edu/StuHome/cabell_f/Density.html