in a given orbital, does the path the electron takes go INTO the orbital or just the surface?

Question

I remember looking at my chemistry textbooks and seeing the orbitals fashioned as something similar to an inflated balloon, but do the electrons travel solely on the surface of the balloon or both on the surface AND into it (as if the surface were the farthest they could reach)?

hope I didn't totally screw up the question I had in mind.

Answer 1

The inflated-balloon looking shape IS the electron. It is the probability distribution of the electron, and you will usually see a statement such as "at 90% probability density" etc. in a textbook, meaning that you are seeing 90% of the electron density.

All the crap you learned about in middle-school and high-school about the fixed paths, etc. is a simplification to the point of wrongness. When (if) you take physical chemistry or quantum mechanics in a physics class you will learn that electrons (and all particles) are described by wavefunctions (literally, mathematical functions that have cosine and sine type components). That's literally what particles are to us--mathematical functions. We cannot directly see them, we cannot directly touch them, every single thing we know about them is because every single thing we can measure about them is just consistent with our mathematical equations describing them. So the wavefunction describes an electron. The square (simple, mathematical square) of the wavefunction describes its density, and that is the function that you see plotted when you see the inflated balloons. So a more correct answer to your question would be that you are seeing the mathematical square of an electron, but essentially, you're seeing an electron. It's not "captured" inside, it's not "floating" on the surface, it IS that balloon shape. I know it's weird, but it's quantum mechanics, it's not supposed to make sense, it just works and describes everything from an electron around a nucleus to semiconductors and chemical reactions and everything else.

Answer 2

I think there are two ways (maybe more) to look at this, the way I'm familiar with is the quantum mechanics way (using molecular orbital theory I think). This theory says the electron is not actually a discrete object so we don't really know exactly where it is at a particular time. Instead we know the probability that it is in a given region at a particular time. What this means is that the orbital is a region in space where we think the electron is floating around in but we are not quite sure where. The other model (valence bond theory I think) looks at the atomic structure of molecules like the solar system with the nucleus being the sun and the electrons being the planets and orbiting the sun. I'm not sure exactly how the orbitals plays into this.

Answer 3

The simplest answer is that the electrons (whether they are real or a mathematical fantasy) can be anywhere, but are more than likely, most of the time, to be somewhere in the solid shape described by diagrams looking like "inflated balloons"!