Properties of Covalent Molecules and Giant Covalent Structures

The video tutorial explains the properties of covalent molecules, highlighting their strong internal bonds and weak intermolecular interactions, leading to low melting and boiling points. It discusses the conditions required for covalent molecules to conduct electricity, noting their lack of charged particles. The formation of polymers from monomers and their properties, such as high melting points due to strong intermolecular forces, are covered. Finally, the video explores giant covalent structures like diamond and silica, emphasizing their stability, high melting points, and inability to conduct electricity, with graphite as an exception.

What is the primary reason covalent molecules have low melting and boiling points?

• High molecular weight

• Weak interactions between molecules

• Presence of charged particles

• Strong covalent bonds within molecules

Which of the following is necessary for a covalent molecule to conduct electricity?

• Strong covalent bonds

• High molecular weight

• Weak intermolecular forces

• Presence of charged particles

What are monomers?

• Large molecules with high melting points

• Reactive molecules that form polymers

• Molecules with weak intermolecular forces

• Neutral molecules that conduct electricity

How does increasing the length of polymer chains affect their properties?

• Increases melting points

• Increases electrical conductivity

• Decreases molecular weight

• Decreases melting points

Which element can form giant covalent structures?

• Nitrogen

• Carbon

• Oxygen

• Hydrogen

What is a characteristic property of giant covalent structures?

• Low melting points

• Hardness and strength

• High electrical conductivity

• Solubility in water

Which giant covalent structure is an exception in terms of electrical conductivity?

• Graphite

• Silica

• Silicon dioxide

• Diamond