Answer:
To absorb neutrons before the neutrons can initiate more fusion reactions.
Explanation:
Control rods, usually made of compounds like graphite, absorb neutrons and prevent them from going everywhere and bombarding other molecules of the radioactive compound being used, usually U-238, and prevent a chain reaction from starting. When U-238 is bombarded with a neutron, it releases 3 others, which hit 3 molecules of U-238, releasing 27 neutrons in total, and so on. This must be controlled, otherwise an uncontrolled chain reaction could easily become highly explosive (Nuclear bombs that utilise U-238 use this principle to cause a chain reaction at a larger scale that releases huge amounts of energy that cause the initial explosion when the atom bomb is detonated).
This question is unfortunately incomplete as the graph is not visible. The options given are:
<span><span><span><span>A) Red
parrots have become less common in the last 200 years.</span>
</span>
</span></span>
B) There
are probably less green parrots today than there once were.
<span><span><span>
</span>
</span></span>
C) Blue
parrots probably are the best adapted species to live on farms.
<span><span><span>
</span>
</span></span>
D) The
blue parrot population has likely increased in the last 200 years.
The answer is B. This is because the graph shows the highest number of green parrots in the 'deep forest' category of environment, whereas the numbers in the 'grassland' and 'scrub forest' are less. Since the forested area in Brazil has decreased rapidly, this means that the preferred environment of the green parrot has decreased, probably resulting in a decline in the green parrot population
<span><span><span>
</span>
</span></span>
c. girls may be more easily hurt and distraught by frequent changes in friendships
