Chemie

Gringer, CC BY-SA 3.0, via Wikimedia Commons

We need a Undedicated metal like Zinc and a noble metal like Copper.
Zn = Zn²⁺ + 2e^- (electrons go away = undedicated metal; through the electrons that travel to the copper electrode)
Cu + 2e- = Cu (Through the electrons from Zinc electrode)
Saltbridge funtion: New Ions - for equality
Electrons flow from zinc (anode) to the copper (cathode). They travel on the cable.

Electronegativity: ability to attract a pair of non-bonding electrons