# Substances with high physical expansive property/expansion after reaction

I want to know if there is a substance/mixture of substances that expands more on some chemical or physical change, than what I've already seen.

Elephant toothpaste is a good example, a small amount of two substances expands into something with much more volume.

The list I have created so far is:

1. Diaper jelly
2. Orbeez
3. Elephant toothpaste
4. Water $$\ce{->}$$ Ice

A list of multiple substances with most expansive chemical or physical property will be appreciated.

The reason for my question: trying to develop a realistic 'smoke bomb' or some sort for a project photography. Best result would be lets say from small pellet, to huge smoke cloud.

• Another example is the pharaoh serpent. But the question could be more defined. – Alchimista Apr 15 at 8:40
• Can you provide parameters for an acceptable final product? For example, I don't think you are including vaporization which increases volume much more than any of the reactions you've cited. – Andrew Apr 15 at 12:10
• If you want large amounts of smoke, take a bunch of straw and sprinkle some water on it, and then burnt it. Although I am not sure how environmentally safe it is. – Shoubhik R Maiti Apr 15 at 16:32