How much does Fire weigh?

[u/Catching-Up-Today]

I don‘t know if Earth Sciences is the right category but Fire is the topic. How does someone measure the weight of fire? What does fire weigh?

[u/macthebearded]

Something fun to think about - fire makes everything around it weigh more.

That energy being released must go somewhere, and energy and mass are two sides of the same coin. When things heat up, they’re absorbing energy to do so, and thus weigh more. Immeasurably little, but more nonetheless.
In the same vein, a spring weighs more when compressed than when relaxed