Final answer:
The central atom in a molecule typically has the lowest electronegativity, making it the anchor around which other higher electronegative atoms, like hydrogen and halogens, are arranged terminally.
Step-by-step explanation:
In a molecule, the central atom is generally the one with the lowest electronegativity. Atoms such as hydrogen and the halogens, which typically exhibit higher electronegativities, are usually found at terminal positions within the molecule. Electronegativity itself is a measure of an atom's ability to attract electrons in a chemical bond, and it varies across different elements. Fluorine, for example, is known for having the highest electronegativity, while cesium has the lowest among the stable elements. As a result, the central atom in a molecule is usually not fluorine or a halogen but rather an element with a lower electronegativity that can form multiple bonds and thereby stabilize the molecular structure.