Final answer:
The remaining cation at step (g) must be properly identified and its charge determined before the final step of the reaction process can be completed, ensuring a balanced chemical equation.
Step-by-step explanation:
The final step that must be performed involving the remaining cation at step (g) is likely to be some sort of reaction or process that will complete the chemical equation provided. Before this final step is performed, the cation at g must be properly identified with its correct formula and charge so the balanced chemical equation can be completed. This is crucial because the exact substances involved determine the products and outcomes of a chemical reaction. Reviewing the concept of a cation, which is a positively charged ion, can help us understand why it is important to know the charge. For instance, the sodium atom has one valence electron, which it loses to become a sodium ion, thereby making it isoelectronic with a noble gas. In the case of magnesium, it loses two electrons to form the magnesium ion. Knowing the charges helps to predict the products after cations and anions 'switch partners' in double replacement reactions. In the provided scenarios, like the reaction between CaO(s) and SiO2(s) making CaSiO3 (l), knowing the balance between ions allows us to understand the stoichiometry of the reaction and ensure the chemical equation is balanced correctly. This is part of the problem-solving steps that include writing the symbol and charge of the cation and anion properly.