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How does lightning form?
Quick answer
Lightning forms when charges separate inside a storm cloud — light positive charge near the top, heavy negative charge near the bottom. When the difference grows large enough, it overcomes the air's resistance and discharges as a giant spark. Rising and falling ice and water in a cloud separate electric charge.
Step by step
- Rising and falling ice and water in a cloud separate electric charge.
- Negative charge builds at the cloud base, positive on the ground below.
- When the voltage is high enough, air breaks down and a spark jumps.
- The bolt heats air so fast it explodes outward as thunder.
People also ask
What causes lightning?
A buildup of separated electric charge in storm clouds that discharges as a massive spark.
Why does thunder follow lightning?
Lightning superheats the air, which expands explosively and creates the sound wave we hear as thunder.
Why do we see lightning before hearing thunder?
Light travels far faster than sound, so the flash reaches us almost instantly while the sound lags behind.
Part of the guide: Water & Weather Phenomena →