in a chemical reaction, the total mass of the substances before the reaction compared to the mass of the substances after the reaction is ? (greater, smaller, equal)

Light waves travel than sound waves.

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?

When an experimenter draws a conclusion that he assumes will apply to all situations set up similarly to his test situation, even though he cannot possibly have examined all possible test scenarios, the experimenter is using deductive reasoning inductive reasoning abductive reasoning subjective reasoning