Final answer:
Non-metallic elements such as Hydrogen, Nitrogen, Oxygen, Fluorine, Noble Gases often appear as gases or brittle, dull-looking solids at room temperature, in contrast to the shiny, solid, often malleable and ductile appearance that characterizes metals.
Step-by-step explanation:
Without specific information about which elements were tested, it is difficult to provide you with a definite answer as many elements can lack a metallic appearance. However, most typically, the non-metallic elements found on the right side of the periodic table, often have characteristic appearances that are non-metallic.
These include elements such as Hydrogen, Nitrogen, Oxygen, Fluorine, and Noble Gases. These elements often appear as gases or brittle, dull-looking solids at room temperature, in contrast to the shiny, solid, often malleable and ductile appearance that characterizes metals.
Learn more about Non-Metallic Elements