- Identify the atomic number from the subscript (\(Z = 17\)), which defines the number of protons and, for a neutral atom, the number of electrons.
- Determine the number of neutrons using the formula \(n^{0} = A - Z\), where \(A\) is the mass number (superscript \(35\)).
- Perform the subtraction: \(35 - 17 = 18\).
- Conclude that there are \(17 \ p^{+}\), \(17 \ e^{-}\), and \(18 \ n^{0}\), which is \(\boxed{17 \ p^{+}, 17 \ e^{-}, 18 \ n^{0}}\).
Explanation
- Identifying Atomic Data
The notation \({ }_{17}^{35} \text{Cl}\) provides specific information about the atomic structure of chlorine-35. The lower number (subscript) \(Z = 17\) is the atomic number, which represents the number of protons in the nucleus of the atom. In a neutral atom, the number of electrons is equal to the number of protons, so there are also \(17\) electrons. The upper number (superscript) \(A = 35\) is the mass number, which is the sum of protons and neutrons in the nucleus.
- Calculating Neutrons
Since the mass number \(A\) is the total count of protons and neutrons, we can find the number of neutrons \(n^{0}\) by subtracting the number of protons \(Z\) from the mass number \(A\):
\[n^{0} = A - Z\]
Substituting the values \(A = 35\) and \(Z = 17\):
\[n^{0} = 35 - 17 = 18\]
Therefore, the atom has \(18\) neutrons.
- Final Counts
Based on the analysis, a neutral atom of chlorine-35 (\({ }_{17}^{35} \text{Cl}\)) contains \(17\) protons, \(17\) electrons, and \(18\) neutrons.
The final results are:
\(\boxed{17 \ p^{+}, 17 \ e^{-}, 18 \ n^{0}}\)
Examples
Understanding the composition of isotopes is fundamental in various fields, such as radiocarbon dating or medical imaging. For instance, in PET (Positron Emission Tomography) scans, scientists use specific radioactive isotopes with known numbers of protons and neutrons to track metabolic processes in the human body. By calculating the difference between mass numbers and atomic numbers, chemists and physicists can determine the stability of an isotope and predict how it will behave in chemical reactions or medical applications.