How to pronounce “ionization” in English

So once again, the universe starts to ionize.And the state of partial ionization, and later on in different locales, fully ionized plasmas come into existence.So this is a brief history of the universe.

So this is the timeline of the universe.So a state of partial ionization-- as I mentioned, hydrogen atoms, electrons, and protons-- they come into existence.And there is a particular spectral line.

Whereas for an oxygen, it needs around 550.So by tuning the x-ray energy to match these ionization energies, you get to choose which of these atoms within the molecule the x-ray is going to ionize.And any excess energy left after an x-ray has ejected an electron will be taken by that electron as kinetic energy.

Now we shine that x-ray pulse on a molecule, and when it hits the molecule, it will ionize the molecule and it ionizes predominantly from these inner shells from the very core parts.The thing is, core level electrons from different elements have different ionization energies.So if you want an x-ray to eject a core level electron from a nitrogen, it needs around 400 electron volts.

And so this is about 15 billion years ago.And as the universe expanded and cooled, various stages of ionization of the matter come into existence.And then the bottom shows the present state of the universe, where we see galaxies, stars,

So its ionization energy will actually be slightly lower.Whereas if you have a lower electron density than average around an atom, those core level electrons will be bound more tightly with a higher ionization energy.Therefore, when you measure the kinetic energy of the electrons you eject, you can use the difference between the input x-ray energy and the output kinetic energy to infer what that electron density was.