Question

What is the neutron : proton ratio for the nucleus ${}_{82}^{206}Pb$ ?

Answer 1

Hint: By using the mass number of an element we can find the number of protons and neutrons which are present in the particular elements. Without knowing the mass number of an element we cannot find the neutron to proton ratio in an element.

Complete answer:
- In the question it is asked to write the neutron to proton ratio for the given nucleus ${}_{82}^{206}Pb$ .
- The atomic number of an element given information about the number of protons and electrons present in the given element.
- The atomic number for the given element ${}_{82}^{206}Pb$ is 82.
- Means the number of protons present in the given element ${}_{82}^{206}Pb$ is 82.
- Now we have to find the number of neutrons present in the given element.
- The formula to calculate the number of neutrons in an atom is as follows.
The number of neutrons in an atom = Mass number of particular atom – number of protons present in the atom
- By using the above formula we can calculate the number of neutrons present in the given nucleus ${}_{82}^{206}Pb$ .
- The mass number of the given nucleus ${}_{82}^{206}Pb$ is 206.
- Therefore the number of neutrons in ${}_{82}^{206}Pb$ = 206 – 82 = 124.
- Therefore the neutron : proton ratio in ${}_{82}^{206}Pb$ is 124 : 82 = 62 : 41.

Note:
Without knowing the atomic number and the mass number of an atom we cannot find the neutron to proton ratio of any element. We have to remember one thing, different isotopes will have different neutron to proton ratios.