The evaporation of hand sanitizer is an endothermic reaction. This phase change, from liquid to vapor requires heat and the alcohol takes the heat from your hand to evaporate. Therefore you feel cooler. It is a physical change, not a chemical change.
A chemical reaction.
The bubbles in hand sanitizer are typically formed from alcohol molecules trapping air as the sanitizer is dispensed. This creates a foamy texture that helps to spread the sanitizer evenly over the hands when rubbed together.
A waterfall is not a chemical reaction.
A chemical reaction is a change in which one kind of matter changes into a different kind of matter with different properties. Reactant is a substance used in a chemical reaction and a product is a substance made in a chemical reaction. Hope this is helpful! ;)
double-displacement reaction.
A chemical reaction is a change in which one kind of matter changes into a different kind of matter with different properties. Reactant is a substance used in a chemical reaction and a product is a substance made in a chemical reaction. Hope this is helpful! ;)
A chemical reaction.
An exothermic reaction is one that proceeds with the evolution of heat.
Photosynthesis.
A chemical reaction is a change in which one kind of matter changes into a different kind of matter with different properties. Reactant is a substance used in a chemical reaction and a product is a substance made in a chemical reaction. Hope this is helpful! ;)
At least one change in chemical bonding.
A waterfall is a physical process, not a chemical reaction. It involves the flow of water over terrain due to gravity, and does not involve a chemical change in the water molecules themselves.