It's not about which object *gets* more electrons, but rather which object *loses* more electrons. When two objects are rubbed together, one object will become positively charged because it loses electrons, while the other object will become negatively charged because it gains electrons.

Here's how it works:

* Triboelectric Effect: This is the phenomenon where static electricity is generated by rubbing two materials together.

* Electronegativity: Different materials have different tendencies to hold onto their electrons. Materials with higher electronegativity are more likely to attract electrons from materials with lower electronegativity.

* Electron Transfer: When two materials with different electronegativities are rubbed together, electrons transfer from the material with lower electronegativity to the material with higher electronegativity.

Example:

If you rub a rubber balloon on your hair, the rubber balloon will become negatively charged and your hair will become positively charged. This is because rubber has a higher electronegativity than hair, so it attracts electrons from your hair.

In short, the object that becomes negatively charged is the one that gains electrons, while the object that becomes positively charged is the one that loses electrons.