To identify the isotope created, we start with the original atom that has 40 protons and 51 neutrons.
- The number of protons (40) indicates that the element is Zirconium (Zr), as Zirconium has an atomic number of 40.
- The mass number can be calculated as the sum of protons and neutrons: 40 protons + 51 neutrons = 91.
So, the original isotope is Zirconium-91 (Zr-91).
Now, when two neutrons are added, the new number of neutrons becomes 51 + 2 = 53. The number of protons remains the same at 40.
Now we can calculate the new mass number:
- New mass number = 40 protons + 53 neutrons = 93.
The new isotope is Zirconium-93 (Zr-93).
Thus, the correct response is:
Zirconium-93.