Signs that say “do not use near an open flame” refer to a

Compare and contrast physical changes with chemical changes.

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?

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?