A firework is set off inside a sealed, insulated chamber. The table shows changes in energy stores during the explosion. No other energy stores change.
| Energy store | Change |
|---|---|
| Chemical energy store of the firework powder | decreases by 960 J |
| Kinetic energy store of the gases | increases by 510 J |
| Thermal energy store of the gases | unknown |
Calculate the increase in the thermal energy store of the gases and state the change in the total energy of the system.