The answer is B. Centrifugation
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Answer: The correct answer is A
Explanation:
On addition of the ammonium nitrate to 50 ml of water the temperature decreases which means that reaction between the ammonium nitrate and water is an endothermic reaction.The value of
is positive for an endothermic reactions.

Entropy is a degree of randomness of the system.
On addition of the ammonium nitrate to water ammonium nitrate break down into ions which means that entropy is increased.

(Gibb's free energy)
Since, ammonium nitrate is getting dissolved in water which means that this reaction is spontaneous and
of spontaneous reaction is negative that is:

The statement that accurately describes dark matter is that It is invisible and It does not emit electromagnetic radiation.
<h3>What is dark matter?</h3>
Dark matter is defined as the particles that makes up most of the mass of galaxies and galaxy clusters. They are also responsible for the way galaxies are organized on grand scales.
The features or characteristics of dark matter is that they are invisible and they do not emit electromagnetic radiation.
Learn more about electromagnetic radiation here:
brainly.com/question/1408043
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