Why do surfaces exposed to the sun get so dusty

The top of a bookcase or tabletop exposed to the sun soon shows a thin surface of dust. It s not just that sunlight makes the dust more visible rather, it is because light from the sun actually promotes the collection of the dust. 

The simplest form of such photo-dissociation is that when one of the fragments is simply an electron  

By convention, the groups of atoms formed during photo-dissociation are usually called fragments. 

The table top acquires a positive charge because it was originally charge neutral, and an electron was lost following photo-dissociation. 

Photo-ionization of nitrous oxide in the upper atmosphere only occurs with light of wavelengths shorter than 134 nm, to cause the reaction NO + /7v - NO+ + e-. 

---