Final answer:
In the half-reaction 2 Na → 2 Na+, two electrons are lost as two sodium atoms are oxidized, each losing one electron to become sodium ions.
Step-by-step explanation:
The half-reaction 2 Na → 2 Na+ illustrates the process of sodium atoms losing electrons to form sodium ions. In this reduction-oxidation (redox) half-reaction, there is a loss of electrons.
Each sodium atom (Na) loses one electron to become a sodium ion (Na+), and since the reaction shows two sodium atoms, a total of two electrons are lost. This change in electron count reflects a change in the oxidation state of sodium from 0 to +1, indicating an oxidation process.
During redox reactions, electrons transferred from one substance to another. This half-reaction specifically shows the oxidation part, where sodium is being oxidized.
It's necessary to balance not only the number of atoms but also the overall charge. Here, sodium atoms start neutrally charged, and each becomes positively charged upon losing an electron, leading to a balanced charge by accounting for the two lost electrons.