Answer:
The independent variable is the condition that you change in an experiment. It is the variable you control.
Explanation:
It is called independent because its value does not depend on and is not affected by the state of any other variable in the experiment. Sometimes you may hear this variable called the "controlled variable" because it is the one that is changed.
I'm not so sure but I would say Answer Choice B
Answer:
Then, at some point, these higher energy electrons give up their "extra" energy in the form of a photon of light, and fall back down to their original energy level.
Explanation:
When properly stimulated, electrons in these materials move from a lower level of energy up to a higher level of energy and occupy a different orbital.
NaCI is the answer, in what my teacher taught me.
Hope I helped :)