A static electric spark occurs when an object with a surplus of negative electrons comes close to another object with less negative charge – and the surplus of electrons is large enough to make the electrons “jump.” The electrons flow from where they've built up – like on you after walking across a wool rug – to the ...

How do sparks occur?

An electric spark is an abrupt electrical discharge that occurs when a sufficiently high electric field creates an ionized, electrically conductive channel through a normally-insulating medium, often air or other gases or gas mixtures.

What causes the spark of lightning?

Lightning is created when water drops are churning around in a thundercloud. They gather either positive or negative electrical charges, so that soon one cloud may be positive and another cloud may be negative. The electrical pressure that builds up must be extremely high for lightning to start.