Is turning the lights off a physical or a chemical change? explain why?

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?

The diagram shows the relationship between scientific disciplines. the names of some scientific disciplines have been removed from the boxes. which scientific discipline belongs in the blue box? a. physics b. biology c. chemistry d. metallurgy

The empirical formula of a compound is ch2o and its mass is 120 amu/molecule, what is its formula?