Question

Which of the following material is not a semiconductor.

• A. Germanium
• B. Graphite
• C. Silicon
• D. Copper oxide

Answer 1

The Correct Option is B

To determine which of the given materials is not a semiconductor, let's analyze the properties of each option:

1. Germanium: Germanium is a classic semiconductor material used in the early development of electronic devices. It has properties that allow it to effectively conduct electricity under certain conditions, making it a semiconductor.
2. Graphite: Graphite is a form of carbon and is known for its good electrical conductivity. However, it is not considered a semiconductor. Instead, it is more correctly classified as a conductive material due to its electron delocalization within the carbon layers.
3. Silicon: Silicon is the most widely used semiconductor material in the electronics industry. It forms the basis of most modern electronic devices, including transistors and integrated circuits.
4. Copper oxide: Copper oxide can exhibit semiconductor properties, particularly in its cupric oxide form (CuO), which is used in various applications like solar energy conversion.

Based on the analysis, Graphite does not fit the criteria for being classified as a semiconductor, although it is a good conductor of electricity. Therefore, the correct answer is: Graphite

Answer 2

The question asks us to identify which one of the given materials is not a semiconductor. Let's review the options one by one:

1. Germanium: Germanium is a well-known group IV element and a semiconductor. It has four valence electrons, which make it suitable for forming covalent bonds that create a crystal lattice. It is widely used in electronic devices.
2. Graphite: Graphite is an allotrope of carbon, where carbon atoms are arranged in a hexagonal pattern. It has excellent electrical conductivity because of the delocalization of electrons in its structure, but it is not classified as a semiconductor. Instead, it is known as a conductor or metallic conductor.
3. Silicon: Silicon is another group IV element like germanium and is one of the most abundant semiconductors used in the electronics industry. It forms the basis of most semiconductor devices.
4. Copper oxide: Copper oxide can behave as a semiconductor in certain phases, such as CuO, which are used in semiconductor applications like solar cells.

From this analysis, we can conclude that Graphite is not a semiconductor. Therefore, the correct answer is Graphite. Graphite is primarily used in applications where its conductivity and thermal properties are beneficial, such as in batteries and as a lubricant, but does not function as a semiconductor in electronics.