Final answer:
To find the number of protons, neutrons, and electrons in isotopes, we use atomic and mass numbers. Technetium-99m has 43 protons, 56 neutrons, and 36 electrons. Iodine-131 has 53 protons, 78 neutrons, and 54 electrons; Thallium-201 has 81 protons, 120 neutrons, and 80 electrons; Xenon-133 has 54 protons, 79 neutrons, and 54 electrons.
Step-by-step explanation:
Determining Protons, Neutrons, and Electrons in Isotopes
To determine the number of protons, neutrons, and electrons in isotopes, we use the atomic number, mass number, and charge if available:
Technetium-99m: Atomic number 43 and mass number 99, charge of 7+. This isotope has 43 protons, 99 - 43 = 56 neutrons, and because of the 7+ charge, 43 - 7 = 36 electrons.
Iodine-131: Atomic number 53 and atomic mass number 131, charge of 1-. This isotope has 53 protons, 131 - 53 = 78 neutrons, and since it has a charge of 1-, it has 53 + 1 = 54 electrons.
Thallium-201: Atomic number 81 and atomic mass number 201, charge of 1+. This isotope has 81 protons, 201 - 81 = 120 neutrons, and because of the 1+ charge, 81 - 1 = 80 electrons.
Xenon-133: Atomic number 54 and atomic mass number 133, neutral charge. As a neutral atom, this isotope has 54 protons, 133 - 54 = 79 neutrons, and equal number of electrons to protons, hence 54 electrons.
The elements for the isotopes mentioned are Fluorine (F), Molybdenum (Mo), Iodine (I), and Thallium (Tl), respectively.