Final answer:
An element with partially filled highest s or p sub-levels is typically a nonmetal, which can be dull and poor conductors of electricity and heat.
Step-by-step explanation:
Elements with partially filled highest s or p sub-levels are generally characterized as nonmetals, aligning with distinct properties that set them apart in the periodic table. Nonmetals commonly exhibit dull appearances and possess poor conductivity for both electricity and heat, contrasting sharply with the lustrous and conductive nature of metals. The defining feature of nonmetals lies in their electronic configuration, where the highest energy level's s or p sub-levels are incompletely filled.
Main group elements, a broad category that encompasses nonmetals, metals, and metalloids, often see the last electron added to either an s or a p orbital in the outermost shell. This arrangement contributes to the diverse range of properties observed within the main group elements. However, the specificity of the question, focusing on partially filled highest s or p sub-levels, distinctly points towards nonmetals.
Understanding this distinction is pivotal for grasping the elemental behavior and properties associated with different regions of the periodic table. By recognizing the electronic configurations and sub-level occupancy, one gains insights into the fundamental characteristics that define nonmetals and contributes to a comprehensive comprehension of the periodic trends and behaviors of diverse chemical elements.