Final answer:
The sodium ion is composed of 11 protons, 10 electrons, and 12 neutrons, resulting in a sodium cation with a +1 charge (Na+).
Step-by-step explanation:
The composition of a sodium ion typically results from the loss of one electron from a neutral sodium atom. Since a stable atom of sodium contains 11 protons, 11 electrons, and 12 neutrons, when it becomes an ion, the number of protons (11) and neutrons (12) remains the same while the number of electrons decreases by one. Therefore, the correct composition of a sodium ion is 11 protons, 10 electrons, and 12 neutrons.
Thus, the answer to the question is C. 11 protons, 10 electrons, 12 neutrons. This corresponds to a sodium cation with a net charge of +1, often written as Na+.