Final answer:
Solids that insulate better than air are called insulators. These materials, which include plastic and glass, have high resistivity and their charges are bound to atoms, making them poor conductors of electricity. Semiconductors are a different category with intermediate properties that are important in electronics. D) Insulators
Step-by-step explanation:
Solids that are better insulators than air are known as insulators. Insulators are materials that inhibit the flow of electrical current. They are characterized by their high resistivity, which means they have very few free charges available to conduct electricity. These free charges in insulators are mostly bound to atoms and do not move freely. In contrast, conductors have lower resistivity and a large density of free charges that move easily through the material, facilitating the flow of electrical current. Conductors, like copper, silver, and aluminum, are essential for creating circuits and conducting electricity efficiently.
Semiconductors, which include elements like silicon and germanium, have properties between those of insulators and conductors. At lower temperatures, they behave like insulators, but as they warm up, they can conduct electricity, which makes them incredibly useful in the production of electronic components, such as computer chips. Unlike insulators, the conductivity of semiconductors can be manipulated by controlling factors such as temperature and the type and amount of impurities added to them.
Materials such as plastic, wood, glass, and dry table salt are examples of insulators. These substances do not allow charges to easily move through them, with electrons and ions being bound within the structure. Insulators like these are often used to protect us from the dangers of electricity and to ensure that electrical currents are directed properly within electronic devices and power systems.