<span> We look for
evidence. There are numerous natural phenomenon that we can't observe
happening in real-time because they happen over large time scales, or
large spatial scales. But we can observe the effects of these
phenomenon and make predictions about what other effects we should see. </span>
Answer:
<h3>Reactivity is the ability of matter to react chemically with other substances. Flammability is the ability of matter to burn.</h3>
