I've found this fantastic school supply shop, full of art supplies, bunsen burners, pipettes, all manner of prisms and lenses and musical instruments. Along the back are chemicals, copper sulfate solution, acids and powders of all kinds. Where else in the world can you walk into a shopping mall and buy a color blindness test for under $1.
One of the things that caught my eye was the learning kits for children. They have kits to make smelling salts, and kits to make flashing lights, and kits to make little carboard robots. I've bought a water wheel generator kit, which powers an LED and a washing-up liquid soap kit.
Look for it, in Imperial World shopping center, Sukhumvkit Road, 3rd Floor.