The symbol for a radioactive nuclide is ${ }_{84}^{210} Po$. Which statement is correct?
A. The atomic number of the radioactive nuclide is 210.
B. The mass number of the radioactive nuclide is 294.
C. The number of neutrons present in the nucleus of each atom is 126.
D. The number of protons present in the nucleus of each atom is 210.
Answer (1)
The atomic number of the nuclide 84 210 P o is 84.
The mass number of the nuclide 84 210 P o is 210.
The number of neutrons is calculated as the mass number minus the atomic number: 210 − 84 = 126 .
Therefore, the correct statement is that the number of neutrons present in the nucleus of each atom is 126 .
Explanation
Problem Analysis We are given the radioactive nuclide 84 210 P o . We need to determine which of the given statements is correct. Let's analyze the notation and the statements.
Understanding Nuclide Notation The notation Z A X represents a nuclide, where:
X is the chemical symbol of the element.
Z is the atomic number, which is the number of protons in the nucleus.
A is the mass number, which is the total number of protons and neutrons in the nucleus.
Identifying Atomic and Mass Numbers In our case, the nuclide is 84 210 P o . Therefore:
The atomic number is 84.
The mass number is 210.
Analyzing the Statements Now, let's analyze the given statements:
The atomic number of the radioactive nuclide is 210. This is incorrect because the atomic number is 84.
The mass number of the radioactive nuclide is 294. This is incorrect because the mass number is 210.
The number of neutrons present in the nucleus of each atom is 126. The number of neutrons is calculated as the mass number minus the atomic number: N = A − Z = 210 − 84 = 126 . This statement is correct.
The number of protons present in the nucleus of each atom is 210. This is incorrect because the number of protons is equal to the atomic number, which is 84.
Conclusion Therefore, the correct statement is: The number of neutrons present in the nucleus of each atom is 126.
Examples
Understanding the structure of atoms and their nuclei is crucial in various fields. For example, in nuclear medicine, radioactive isotopes are used for diagnostic imaging and cancer treatment. Knowing the number of protons and neutrons in a radioactive isotope helps scientists predict its stability and decay mode, which is essential for safe and effective use in medical applications. Similarly, in environmental science, understanding the composition of radioactive elements helps in monitoring and managing nuclear waste. For instance, 84 210 P o is a naturally occurring radioactive isotope that can be found in the environment and its properties need to be well understood for safety assessments.
