What must be true about the mass of the substances involved in the reaction BEFORE the
change compared to the mass of the substances involved in the reaction AFTER
the change?

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.

Why are people not able to scuba dive in the deep part of the ocean

In the cathode ray tube experiment, j. j. thomson passed an electric current through different gases inside a cathode ray tube in the presence of an electric field. in which two ways did this experiment change scientists’ understanding of the atom?