The section presents a question regarding the atomic number of an element. It asks which element has an atomic number of 6, providing four options: A. Oxy, B. Carbon, C. Nitơ, and D. Helium. The key topic is the identification of elements based on their atomic numbers, and the key entities involved are the elements Oxy (O), Carbon (C), Nitơ (N), and Helium (He).