Which of the following physical properties describes carbon?
Select TWO correct answers.
Conductor
Lustrous
Brittle
Dull
Malleable
The correct answer and explanation is:
The two correct answers are:
- Lustrous
- Brittle
Explanation:
Carbon exhibits a range of physical properties depending on its form. The most common forms of carbon are graphite, diamond, and amorphous carbon. Each form has unique characteristics, but two key physical properties that are relevant across many of these forms are lustrous and brittle.
Lustrous:
Carbon in the form of diamond is highly lustrous. Diamond has an exceptional ability to reflect light due to its crystal structure, making it shiny and attractive. Even graphite, another allotrope of carbon, has some lustrous properties, especially in its natural state as it often has a metallic sheen. This lustrous property is a key feature when considering carbon in its various forms.
Brittle:
Carbon, particularly in its diamond form, is very brittle. Despite being the hardest known natural material, diamond can fracture or shatter under a sharp impact or stress. This brittleness is a defining feature because, while it is extremely hard, it does not bend or deform like more ductile materials. Similarly, graphite, which is made up of layers of carbon atoms, has a layered structure that makes it prone to breaking along these planes.
Not Malleable:
Carbon is not malleable, meaning it does not bend easily. In its diamond form, it is too hard to be shaped or bent. Graphite is also not malleable in the traditional sense, though its layers can slide over each other, making it useful as a lubricant.
Dull:
Carbon in the form of graphite is not dull but rather has a metallic sheen. On the other hand, diamond, being lustrous, certainly does not exhibit dullness.
Conductor:
Graphite is a good conductor of electricity, but diamond is an excellent insulator. Therefore, carbon does not consistently display conductivity across its forms.