Fact 1: Electricity sometimes is used for heating buildings.

Fact 2: Electricity is electrons in motion.

Given the two facts above, answer the question "what is used for heating buildings?" with the following options: 
- electrons in motion
 - protons in motion
 - coiled neutrons
 - one celled organisms
 - Movement of an air mass
 - clouds
 - igniting fuel and oxidiser
 - compound of hydrogen oxygen


 

 electrons in motion        