Production of a gas, color changes, a change in temperature, and the formation of a precipitate are all evidence of a chemical reaction. NGSS 5-PS1-4 ... to indicate the pH of the solution. Label 3 ...

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 ...

Students recognize that a particular color change is a characteristic property of a substance and that a color change can also be used as evidence that a chemical reaction has occurred ... It should ...

A new study from Cardiff and Bristol universities makes it possible to visualise chemical reactions involving small molecules ... This interdisciplinary type of research is close to Dr Carpenter’s ...