Final answer:
The nuclear composition of ^41 v20 Ca is 20 protons, 21 electrons, and 21 neutrons.
Step-by-step explanation:
The nuclear composition of the isotope ^41 v20 Ca is 20 protons, 21 electrons, and 21 neutrons. The atomic number, 20, represents the number of protons in the nucleus. The mass number, 41, is the sum of the protons and neutrons, so to find the number of neutrons, we subtract the number of protons from the mass number. Therefore, the correct answer is 20 protons, 21 electrons, 21 neutrons (option B).