Chemical reactions make new chemicals. Atoms are rearranged during a chemical reaction, but the number of atoms does not change. Evidence of chemical reactions includes a large temperature change ...

An overview of the definitions of different types of chemicals ... ways to distinguish physical and chemical changes. Chemical equations and calculations Reaction information is shown using ...

Because substances are made up of different atoms and molecules, they react in characteristic ways. Production of a gas, color changes, a change in temperature, and the formation of a precipitate are ...

When electricity is flowing, the cathode gains the same number of electrons that the anode loses. This happens through two different types of chemical reactions. The reaction when the cathode gains ...