Why do some things burn and some do not?

Answer 1

some things do that because you put them in the thingy too long. so that's it. and i need some hepl on something. do you know anything about microwave waves for the electromagnetic spectrum, please tell me!!

Under the right conditions, everything will Burn. Burning is a Chemical process known as Oxidation. If you've got enough Oxygen and enough heat you can make anything burn.

Some stuff burns easier because it takes less heat to get it to burn, generally because the molecular bonds are weaker, so it takes less energy to break them and put an Oxygen atom into the mix. Hydrocarbons (Gasoline, Propane, Wood), in perfect conditions, break down into just Carbon Dioxide and Water (Vapour). Since conditions aren't usually perfect, there is leftover Carbon, the ash or charcoal found around most fires.

Also what exactly did you want to know about Microwaves? There's a lot of ground to cover there, from basic wavelength/frequency, to how it cooks your food, to how it transmits power without wires. Get back to me and I'll try to help

It depends mostly on the susceptibility (ability to absorb) of the material to the microwaves. A highly susceptible material will absorb more microwave energy, get hotter faster, and be more likely to burn than a lower susceptible material.

It it also important to time the cooking right. That is why microwave cookers have timers that go down to seconds, as they typically cook fast. Just a few too many seconds is often the difference between properly cooked and completely burned.

To get browning in a microwave cooker a device called a susceptor made of a material with very high susceptibility and the ability to rapidly radiate the heat is used to hold the item being cooked, to generate the dry heat needed to brown the item. These susceptors are usually only one time usable and must be discarded after use to avoid risk of fire if they were to be reused.