The correct option is **C. Gases have very low electrical conductivity compared to liquids and solids because they have few charge carriers.** ### Detailed Explanation: 1. **Understanding Electrical Conductivity:** - Electrical conductivity refers to the ability of a material to conduct electric current. This ability depends on the presence of charge carriers, which can be electrons or ions that move through the material when an electric field is applied. 2. **Conductivity in Different States of Matter:** - **Solids:** In metals, for example, there are many free electrons that can move easily, making them excellent conductors. In ionic solids, conductivity can occur when ions are free to move (e.g., when melted or dissolved in water). - **Liquids:** Many liquids, especially electrolytes, can conduct electricity well because they contain ions that can move freely. - **Gases:** Under normal atmospheric conditions, gases are composed of molecules that are far apart and have very few charge carriers. This means that there are not enough free electrons or ions to carry an electric current effectively. 3. **Why Option C is Correct:** - Gases have very low electrical conductivity because they consist of neutral molecules that do not have free charge carriers. At normal temperatures and pressures, the density of gases is low, and the molecules are not ionized. Therefore, the number of charge carriers is minimal, leading to poor conductivity. 4. **Why the Other Options are Incorrect:** - **Option A:** "Gases are excellent conductors of electricity due to the presence of free electrons." - This statement is incorrect because gases do not have free electrons under normal conditions. The lack of free charge carriers means they cannot conduct electricity well. - **Option B:** "Gases are insulators at low temperatures but become conductors at high temperatures." - While it is true that increasing temperature can ionize some gases (leading to increased conductivity), this statement is misleading. Even at high temperatures, gases generally do not become good conductors like solids or liquids. They may conduct better than at low temperatures, but they still remain poor conductors overall. - **Option D:** "Gases conduct electricity equally well as solids because of their molecular structure." - This statement is false. Solids, especially metals, have a structured arrangement of atoms with free electrons that allow for efficient conduction. Gases, on the other hand, have a much less dense arrangement and lack the necessary charge carriers to conduct electricity effectively. ### Summary of Key Points: - Gases have very low electrical conductivity due to a lack of charge carriers (free electrons or ions). - Compared to solids and liquids, gases are poor conductors of electricity. - Conductivity in gases can increase at high temperatures, but they still do not reach the conductivity levels of solids or liquids. - Understanding the differences in conductivity among states of matter is crucial for grasping concepts in electricity and materials science. This thorough understanding of the electrical conductivity of gases will help you in your studies and exams, ensuring you can differentiate between the conductive properties of various materials.