Short:

Are coal film resistors and metal film resistors equally safe to burn?

Long:

I want to explain to children that they need to carefully calculate and check resistor values. I don't only want to explain it, but also let them feel and see it.

In one step, I use 3 resistors in parallel, operating at their defined 0.25W. They will get hot and the children can feel it. However, this may not show the danger enough, so I also want to let one of them catch fire.

A lot of things are obvious when performing this experiment

• keep the children in a safe distance
• use a fire proof surface
• do the experiment outside, so there's good ventilation
• have a fire extinguisher near, just in case

I was also looking up online sources like Blowing up a resistor and I'm glad that resistors burn but don't explode.

However, there's one open question to me: we have 0.25W carbon film resistors and 0.25W and 0.6W metal film resistors available. Are they equally safe to use?

My assumption would be that the carbon film resistors just burns to ash, but the metal film resistors might melt into liquid metal. Is it maybe even educational to do both experiments, because the result is so different?