The graph shows neutron number versus proton number for stable nuclei. what conclusions can be drawn from the graph?

a. as the number of protons increases, more neutrons are needed to create stable nuclei.

b. as the number of protons increases, the ratio of neutrons to protons decreases.

c. nuclei with more than 20 protons typically have fewer neutrons than protons.

d. nuclei with fewer than 20 protons typically have fewer protons than neutrons.

The correct option is B.
A nucleus is generally considered unstable if the ratio of proton to neutron is less than 1:1 or greater than 1:5.The attractive force present in the nucleus is provided by the neutron and is quite effective at close distances. The higher the number of proton in the nucleus, the higher the number of neutron that is needed to hold the nucleus together. As the nucleus is getting bigger, it will get to a point where the attractive force can not hold the nucleus together again and adding more neutrons will only increase the space between the protons. At this point as the number of proton increases, the ratio of neutron to proton decreases.

Answerthe valence of an element or radical is equal to the number of positive or negative charges on the ion.