"As the difference between the charges in the bottom of the cloud and the earth below it builds up, the first stage of lightning begins.
When the electric field becomes very strong (on the order of tens of thousands of volts per inch), conditions are ripe for the air to begin breaking down. The electric field causes the surrounding air to become separated into positive ions and electrons — the air is ionized. Keep in mind that the ionization does not mean that there is more negative charge (electrons) or more positive charge (positive atomic nuclei / positive ions) than before. This ionization only means that the electrons and positive ions are farther apart than they were in their original atomic structure."
https://science.howstuffworks.com/nature/natural-disasters/lightning2.htm
Lightning is an effect, not the cause itself.
"As the difference between the charges in the bottom of the cloud and the earth below it builds up, the first stage of lightning begins.
When the electric field becomes very strong (on the order of tens of thousands of volts per inch), conditions are ripe for the air to begin breaking down. The electric field causes the surrounding air to become separated into positive ions and electrons — the air is ionized. Keep in mind that the ionization does not mean that there is more negative charge (electrons) or more positive charge (positive atomic nuclei / positive ions) than before. This ionization only means that the electrons and positive ions are farther apart than they were in their original atomic structure." https://science.howstuffworks.com/nature/natural-disasters/lightning2.htm
So, what exactly, precisely is that atomic force?