Which of the following nuclei is most stable based on its binding energy? a. silver (ag – 107) b. nitrogen (n – 15) c. gold (au – 197) d. nickel (ni – 58)

We have that the most stable nuclei are the ones with the highest average binding energy. We see that Nitrogen has a mass number of 15 and that in this region of the graph average binding energy is low. Silver and Gold are along a line where there is a constant decline in average binding energy; silver has more than gold. However, we see that at the start of this decline, there is Fe 56. This region has the elements with the highest average binding energy; Nickel with a mass number of 58 is right there and thus it is the most stable nucleus out of the listed ones.

It maybe because uranus is made of gas but uranus has a solid core in the middle

Lexy is correct because angle r is between the incident wave,  n  = 0, and a diffracted wave.