Chapter 39, Problem 51A

When the isotope bismuth-213 emits an alpha particle, it becomes a new element.

a. What are the atomic number and atomic mass number of the new element?

b. What element results if bismuth-213 emits a beta particle instead?

To determine

The atomic number and atomic mass number of the new element due to emission of one alpha particle.

Answer to Problem 51A

The atomic number of new element is 81 and atomic mass number of new element is 209.

Explanation of Solution

Introduction:

The number of protons in the nucleus of atom is same as the atomic number and sum of number of neutron and proton in the nucleus of the atom is same as the atomic mass number.

The atomic number reduces by two units and atomic mass number reduces by four units due to emission of one alpha particle from a radioactive element.

The atomic number of Bi-213 is 83 and the atomic mass number is 213. If the one alpha particle emits from Bi-213, then the atomic number becomes 81 due to reduction of two unit in atomic number and atomic mass number becomes 209 due to reduction of four units in the atomic mass number.

The atomic number of new element becomes 81 and mass number becomes 209.

Conclusion:

Thus, the atomic number of new element is 81 and atomic mass number of new element is 209.

To determine

The atomic number and atomic mass number of the new element due to emission of one beta particle.

Answer to Problem 51A

The atomic number of new element is 82 and atomic mass number of new element is 213.

Explanation of Solution

Introduction:

The atomic number increases by one unit and atomic mass number remains unaffected due to emission of one beta particle. The one neutron in the nucleus changes into proton. The number off proton is same as the atomic number of the element, so the atomic number increases due to increase of one proton in the nucleus of the element.

The atomic number of Bi-213 is 83 and atomic mass number is 213. If the one beta particle emits from Bi-213, then the atomic number becomes 82 due to increase of one unit in atomic number and atomic mass number remains same.

The atomic number of new element becomes 82 and mass number becomes 213.

Conclusion:

Thus, the atomic number of new element is 82 and atomic mass number of new element is 213.