[tangoblue (OP)]

this is not one of those things that blows your microwave up or damages it by the way, it only leaves a soapy smell.

When you put a BAR of soap into the microwave it rises lick a loaf of bread in the oven.  When you take it out the soap is very light and has air bubbles in it...WHY?

http://www.youtube.com/watch?v=7lAOOwMNodA

[BenV]

WARNING - if you do try this at home bear this in mind:

1. The soap will be very hot when it first comes out

2. Your microwave, and in fact your entire kitchen, will smell of soap for a very long time.

I know.  I've done it.

[tangoblue (OP)]

it looks and feels cool thought huh

[Bored chemist]

This experiment may invalidate the warranty- but I never saw soap with a warranty anyway.

[Chemistry4me]

That video reminds me of an episode from mythbusters. I should give that a try sometime when I have some spare time and soap.

[dvijay]

I Am surprised,why somebody should try to put a soap cake in the microwave oven and start it?

Soap is not a foodstuff that you are cooking.

[Chemistry4me]

Because it is fun [] You should try it sometime, really.

[sadarian]

something more fun is a Compact Disc.  Put it in label side down, cut on the microwave.  Colored sparks will fly for about 10 secs.  Of course your CD is now toast...and quite possibly your microwave too!  Did it before I moved out of my last apt.  (they had already refunded my security deposit)

[daveshorts]

I found that it only worked well with some soaps, the cheap ones don't seem to work so well. I think you need a certain water content in the soap

Of course crisp packets work well too

http://www.thenakedscientists.com/HTML/front/crisp-packet-fireworks/
http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/crisp-packet-in-microwave/

[RD]

Apparently you can melt a beer-bottle in a microwave, (you do have to warm it with a blowtorch first) ...
http://www.metacafe.com/watch/1004040/melt_a_frickn_beer_bottle/

[incolour]

A light bulb in a microwave is also very good! You get some nice plasma.

(I wouldn't recommend you do this though, as it could obviously burst.)