An isotope with 15 protons and 17 neutrons will have which symbol?
A. ${}_{15}^{17} Cl$
B. ${}_{15}^{17} P$
C. ${}_{17}^{32} Cl$
D. ${}_{17}^{32} P$
E. ${}_{15}^{32} P
Answer (2)
Determine the element by the number of protons: 15 protons correspond to phosphorus (P).
Calculate the mass number by adding protons and neutrons: 15 + 17 = 32 .
Write the isotope symbol as Z A X , where Z is the atomic number and A is the mass number: 15 32 P .
The correct symbol for the isotope is 15 32 P .
Explanation
Understanding the Problem We are given an isotope with 15 protons and 17 neutrons. We need to determine its symbol from the given options.
Identifying the Element The atomic number (number of protons) defines the element. The number of protons is 15, which corresponds to the element phosphorus (P).
Calculating the Mass Number The mass number is the sum of protons and neutrons. In this case, it is 15 + 17 = 32 .
Writing the Isotope Symbol The symbol for an isotope is written as Z A X , where Z is the atomic number, A is the mass number, and X is the element symbol. Therefore, the symbol for this isotope is 15 32 P .
Final Answer Comparing our result with the given options, we find that the correct symbol is 15 32 P .
Examples
Isotopes are used in various fields, such as carbon dating in archaeology to determine the age of ancient artifacts. For example, carbon-14, an isotope of carbon, is used to estimate the age of organic materials. Understanding isotopes and their symbols is crucial in nuclear chemistry and related scientific disciplines. In medicine, radioactive isotopes are used in imaging techniques like PET scans to diagnose diseases.
The symbol for the isotope with 15 protons and 17 neutrons is 15 32 P . This is determined by recognizing that 15 protons identify it as phosphorus and the mass number, calculated by adding protons and neutrons, equals 32. Thus, the correct answer is option E: 15 32 P .
;
