Answer:
Y= 98, 0% , Z = 94,7 %
Explanation:
We use simple 3 rules to find the percentage of purity, using mass data:
Sample Y =
85g----100%
83,30g----X = (83,30gx 100%)/ 85g= 98, 0%
Sample Z =
95g----100%
90g----X = (90gx 100%)/ 95g= 94, 7%
Answer:
A
Explanation:
At the start of a drought, groundwater may not be noticeably lower (not B). Only aquifers near the ocean may become contaminated with salt water (not C). And it is definitely not D.
The correct answer is C. Here's why:
Choice A is illogical. A single experiment does not confirm a theory as true. Multiple successful trials are needed for one to even consider a hypothesis to be accepted as a theory.
Choice B is wrong. If a scientist finds a new way to test a hypothesis, experimental methods do change. Note that when there are additional ways to test a hypothesis, a scientist should test it with additional methods.
Choice D is incorrect. If someone finds a way to test a new hypothesis, it would not be made into law since there is more information regarding the theory. This means that it would remain a theory until one can prove that it can't be tested using different methods.
