I don't know what the options were but a material that is very likely going to be challenging to recognize under a microscope as a mixture is a homogeneous mixture. A homogenous mixture is uniform and thus hard to recognize as a mixture. An example is water!
The tilt of the earth provides the earth with seasons. As the earth revolved around the sun different portions (northern or Southern Hemisphere) is exposed more directly to the suns radiation, thus it is hotter in those regions. (Why the United States experiences winter in December but Australia experience summer in December.)
Answer :
B
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Answer :]
to convert from g NaOH to mol NaOH. = 1.48 g NaOH are needed to neutralize the acid.
Answer:
, 
Explanation:
The change in energy is given by the change in gravitational potential energy:



The average rate of change in terms of time is approximately this:


