Carbon has all of these physical properties except
A. Dull solid
B. Good conductor
C. Solid state of matter
D. Brittle
The correct answer and explanation is:
The correct answer is B. Good conductor.
Carbon is a non-metal and generally not a good conductor of electricity in its typical forms, such as graphite and diamond. Let’s break this down to understand why:
- A. Dull solid: Carbon in its most common form, like graphite, is a dull solid. It does not have the shiny appearance that metals or certain other materials exhibit. This property is true for carbon in many of its allotropes.
- B. Good conductor: This is the correct exception. While graphite is a good conductor of electricity due to its structure, where each carbon atom is bonded to three others in a layer, and one electron is free to move between the layers, carbon in its other forms like diamond is a poor conductor. Diamond has a very strong covalent bond structure and lacks free electrons, which are essential for conducting electricity. Therefore, carbon as a whole cannot be classified as a good conductor.
- C. Solid state of matter: Carbon is usually a solid at room temperature, in various allotropes, including graphite, diamond, and fullerenes. This is a typical property of carbon.
- D. Brittle: Carbon in the form of diamond is extremely brittle, meaning it can break or shatter easily under pressure. Graphite, on the other hand, is soft and can be used as a lubricant or in pencils, but it still displays some brittleness due to its layered structure.
Thus, carbon’s overall physical properties depend on its allotrope, but in general, it is not considered a good conductor of electricity in its various forms.