How much joules of heat does a 100 W of heater produce if it is operated for 5 min?

The amount of heat produced by the 100 W heater in 5 minutes can be calculated as follows:

Power (in watts) = 100 W Time (in seconds) = 5 minutes * 60 seconds/minute = 300 seconds Energy = Power * Time = 100 W * 300 s = 30,000 joules

So, the heater will produce 30,000 joules of heat.