<u>Answer:</u> The amount of sample left after 20 years is 288.522 g and after 50 years is 144.26 g
<u>Explanation:</u>
We are given a function that calculates the amount of sample remaining after 't' years, which is:
Putting values in above equation:
Hence, the amount of sample left after 20 years is 288.522 g
Putting values in above equation:
Hence, the amount of sample left after 50 years is 144.26 g
The distance from the nucleus at which the electron is most likely to be found
Answer: Option (E) is the correct answer.
Explanation:
A spontaneous reaction is defined as the process which tends to occur on its own. And, a non-spontaneous reaction is defined as a process for the completion of which we have to provide certain conditions.
For example, ice melting at 
is spontaneous primarily due to the increase in molecular disorder (dispersal of matter). Also, melting of ice is taking place on its own without any external force.
It is not necessary that all exothermic reactions will be exothermic in nature.
Thus, we can conclude that the statement all exothermic reactions are spontaneous, is false.
There are so many routes by which water can move through the various stages in the water cycle.
<h3>What is the water cycle?</h3>
The water cycle has to do with the route of movement of water in the enviroment. We have to note that there are so many routes by which water can move through the various stages in the water cycle.
The sun supplies the energy that drives the water cycle. This is seen in the fact that the supply of energy from the sun is required for evaporation to take place.
Learn more about water cycle:brainly.com/question/1151425
#SPJ1
Answer: mutualism, commensalism, and parasitism
Explanation: with mutualism, both partners benefit. With commensalism, only one species benefits while the other is neither helped nor harmed. With parasitism, one organism (the parasite) gains benefits, while the other (host) suffers.
