Physics Cat

Are you cutting it with a laser and microscope? It could get pretty small but pretty useless too

Hypothetically, it could get down to an atom

https://sciencing.com/particles-smaller-atom-8484470.html

You're both wrong, as a pencil is a composite of materials, so it would be multiple types of molecules and atoms. Isolating it to an atom or smaller and it's no longer a pencil.
So really, as thin as you can slice it for a scanning electron microscope slide would be close to it.

Well, you can't exactly "cut" an atom in half, there have to be other means

You can with particle radiation.

That's what I meant by "other means"

(Neutron radiation)

But then it would no longer be a pencil

Mm, true, I used to do this thing where I'd meticulously sharpen my pencil till it was right up against the metal eraser holder. Still used them to write lol.

Then it’s subatomic particles (if the laser is powerful enough and essentially emitting gamma rays). After that you could split it into quarks and gluons (again if powerful enough).

But then again a pencil is the product of multiple molecular chains and stripping it down to graphite, its neutrons (or more realistically its electrons), or its quarks and gluons would make it either graphite, neutrons/electrons, quarks/ gluons and not a pencil.

technically it should be enough to go smaller than an atom, if you were able to split one

Curf, or the width of your cutting tool, would have a lot to do with it. If you use a saw blade to cut it, the width of your cut section would be up to an 1/8 of an inch. So, if your pencil were divided into sections only 1/8" wide, then your pencil would then be disintegrated by the saw blade the next time it cuts. A knife however would create a much smaller curf and could go much smaller. Technically, if you had the means to do it you could get the width down to a few sub-atomic particles that, depending on the strength of the atomic bond they have, would only be nano or even picometers wide. Maybe even smaller. Pretty useless pencil at that point though :)

1.6 x 10^-35 meters

https://www.youtube.com/watch?v=bjVfL8uNkUk

The Planck length is the scale at which classical ideas about gravity and space-time cease to be valid, and quantum effects dominate. This is the 'quantum of length', the smallest measurement of length with any meaning.

And roughly equal to 1.6 x 10-35 m or about 10-20 times the size of a proton.