Category Archives: Chemistry

My Coke runneth over

Diet Coke and Mentos geyser.
Photo by Michael Murphy.

They say you can’t un-break what’s broken, un-see what you’ve seen or put the toothpaste back in the tube. But can you un-shake a can of soda? More to the point, does tapping the top, slapping the sides or flipping the can end-over-end make a difference?

I’ll tell you what I found out, but some of you might not like the answer ….

Does Tapping a Soda Can Prevent it from Foaming Over?

In a microwave, still waters run deep – and dangerous

Michael Bay's microwave
Tick-tock.

In case you’re wondering, yes, microwaves are magic and, yes, they are trying to kill you. Take that seemingly innocuous cup of water that you just heated for your afternoon tea. Shouldn’t that be bubbling by now? After all, you nuked it for an awfully long time.

Come to think of it, what do you really know about that microwave?

Can Water Explode in a Microwave?

Lave Ferrous: The secret lives of magnetic soaps

There’s an old run of Peanuts in which Charlie Brown is repeatedly confronted by girls skipping “hi-fi” jump ropes or wearing “hi-fi” bracelets. Each strip ends with Charlie Brown loudly questioning how such an object can be hi-fi, but of course we know the answer: marketing.

Magnetic soap has that sort of ring to it, too. But there are actually good reasons for making surfactants – the group of surface-tension reducing substances to which soap belongs – stick to magnets. Imagine cleaning up an environmental disaster like the Deepwater Horizon oil spill without leaving any of your cleanup materials behind, and you’ll begin to see what I mean.

Of course, that doesn’t exampling how soap can be magnetic in the first place. For that, you’ll have to read on.

How Magnetic Soap Works