"de Broglie’s conclusion was that an object as small as an electron would act within a wave."

How did they come up with the smallest unit of electron? Math based on other experiments which also ignore the limits of the instruments.

How did they manage to be able to send ONE electron or photon at a time?

What they were shooting every 10 seconds was a tiny bit of energy which they assume is a single electron or photon.

They apply whole numbers calculations to what needs a real number. There is such a thing as an infinitesimally small wave, but they invented the idea of a quantum of electricity or light.

It's like measuring a building in bricks instead of meters which can be 0.00000000000000000001 small.

I will be writing a post on how chemistry and their idea of electron valences (calculated by probability) is better explained with the idea that there isn't just exact whole numbers of electrons.

Example: An atom with 4 protons and 4.000000001 electron (force) can bond to an atom with 8 protons and 7.99999999 electron (force). Whole numbers are the property of protons, not electrons which are not particles but energy (wave).

And that's why the Heisenberg uncertainty principle says you cannot find the electron!