What type of reaction is 4 Fe +3 02 → 2 Fe2O3

What three things determine the shape and size of a puddle when water is poured out onto a surface

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.

Achemical reaction is done in the setup shown, resulting in a change of mass. what will happen if the same reaction is done in a sealed container that is placed on the electronic balance?