Question

pretest: unit 3
the graph shows neutron number vs.
what conclusions can be drawn from the graph?
120
110
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90
80
70
60
50
40
30
20
10
0
10 20 30 40 50 60 70 80
protons
stable nuclide *
a. nuclei with fewer than 20 protons typically have more protons than neutrons.
b. as the number of protons increases, the ratio of neutrons to protons decreases.
c. nuclei with more than 20 protons typically have fewer protons than neutrons.

Explanation:

Analyze each option based on the graph. For nuclei with fewer than 20 protons, points are mostly above the line y = x, meaning more neutrons than protons, so A is wrong. As number of protons increases, points move further above y = x, so neutron - proton ratio increases, B is wrong. For nuclei with more than 20 protons, points are above y = x, indicating more neutrons than protons.

Answer:

C. Nuclei with more than 20 protons typically have fewer protons than neutrons.