Answer:
D) Evaluating it with experimentation and argument.
Explanation:
If you don't have enough observational evidence, then you can't really strengthen your scientific knowledge, because you haven't collected enough information to answer the questions you're asking.
If you only have a few scientists working on a question, it will take longer to find an answer. With more people working on a concept, it can be solved in more time.
It can be good to create new hypotheses, but only if you've already tested your original hypothesis (with experimentation and argument), and it turned out to be wrong. Once you've rejected your first hypothesis, only then should you make a new one.
I think metal K+ produces the light with the highest energy level.
Potassium metal is indeed more reactive than lithium metal, because potassium has a more loosely bound valence electron. In direct reactions, potassium reacts more violently than lithium.
The answer is (1) 90 Sr. The definition of beta decay is that a type of radioactive decay in which one proton will change to one neutron and release one electron inside the nucleus. And 90Sr is a common beta emitter.
