I have noticed when making milkshakes that banana, vanilla and strawberry flavour powders sink immediately and dissolve, and take a long time to seperate from the milk.  On the other hand, chocolate powder floats on the surface, taking a long time (in excess of 20 minutes) to completely sink to the bottom, and then easily seperates into lumps and layers, requiring near constant mixing to kee it dissolved.

Does anyone know what difference there is between chocolate powder and other powders that gives it such different qualities?

On a banana, purchased from a supermarket this July, I noticed a white lump on the surface, near to the top. When scraped, the silky membrane detached easily, revealing tens of (presumably) eggs beneath. The eggs were spherical, opaque white, and very delicate, bursting easily when touched. They were around the size of a grain of granulated sugar. The banana surface was soft underneath the eggs. The lump and silk around it covered an area around 2cm long and wide. At the tip of the lump was a spec of dark brown, brittle material. 

We were in physics a few days ago and we were studying radioactivity, our teacher mentioned that even bananas contain radioactive elements. So I was wondering, how many bananas do you theoretically have to eat to get radiation poisoning?

At school we have been learning about metals reacting with acid.  I had a look at the periodic table and I saw that pottasium (K)  was an alkali metal.  I also knew that bananas are an excellent source of pottasium.  So why, when I eat a banana, does the hydrochloric acid in my stomach not react and make me explode?

Felix, 11, Norwich