How did dalton describe the relationship between atoms and elements?

Nonmetal halogen family atmoic mass 35

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.