For an element characterized by a mass number of 80 and an atomic number of 40, the neutron-to-proton ratio evaluates to ___________________?
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Answer: A. 1
Explanation
For an element with mass number eighty and atomic number forty, the neutron-to-proton ratio evaluates to one. Subtracting forty protons from the eighty total nucleons leaves exactly forty neutrons in the nucleus. Dividing the forty neutrons by the forty protons results in a simple ratio of one. The neutron-to-proton ratio determines the nuclear stability of an atomic isotope. Light stable nuclides typically have a ratio close to one, while heavier nuclides require more neutrons. Atomic number defines the element, which in this case is zirconium with forty protons.
Nuclear chemists calculate neutron-to-proton ratios to predict whether an isotope will undergo radioactive decay. Stable isotopes cluster along a specific nuclear stability belt on charts of nuclides. Isotopes deviating significantly from optimal ratios are unstable and emit radiation to achieve balance. A ratio of 0.5 would imply half as many neutrons as protons, which mismatches this nucleus. A ratio of 2 would mean twice as many neutrons as protons, contradicting the calculation. A value of 4 is an arbitrary number unrelated to this specific subatomic particle ratio.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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