Final answer:
Na_3P is sodium phosphide (a), while Na_3PO_4 is sodium phosphate, which isn't listed in the options but is often confused with similar-sounding compounds.
Step-by-step explanation:
The chemical compound Na3P is correctly referred to as sodium phosphide, which is the answer to Exercise 3.10.1 (a). Meanwhile, Na3PO4 represents sodium phosphate and is not listed among the options provided. It's important to understand the composition and naming conventions of ionic compounds, which often involve a metal (like sodium) bonded to a non-metal or polyatomic ion (like phosphide or phosphate).
Challenges such as these test a student's ability to recognize and name ionic compounds based on their chemical formula. Compounds like sodium phosphate and sodium phosphide have different uses and properties in the field of chemistry, indicative of the significance of correct compound identification.