During a firework display, the firework and its surroundings are treated as a closed system. All changes during the burn are accounted for by the three rows in the table.
| Energy store | Initial energy | Final energy |
|---|---|---|
| Chemical | 700 J | 400 J |
| Kinetic | 150 J | 300 J |
| Thermal | XXX | 550 J |
Which value is XXX, the initial energy in the thermal store?
400 J400\ \mathrm{J}400 J
700 J700\ \mathrm{J}700 J
850 J850\ \mathrm{J}850 J
550 J550\ \mathrm{J}550 J