GCSE Chemistry - Properties of Simple Molecular Substances & Giant Covalent Structures #17

The video tutorial explains covalent bonds, focusing on simple molecular substances and giant covalent structures. Simple molecular substances, like chlorine, have low melting and boiling points due to weak intermolecular forces. In contrast, giant covalent structures, such as diamond and silicon dioxide, have high melting and boiling points due to strong covalent bonds. The video also highlights that simple molecular substances do not conduct electricity, while graphite, a giant covalent structure, is an exception. The tutorial concludes with a focus on the structure of silicon dioxide.

What is the primary reason that simple molecular substances like chlorine have low boiling points?

• Strong covalent bonds within molecules

• Weak intermolecular forces between molecules

• High energy required to break covalent bonds

• Presence of free electrons

As you move down the group in the periodic table, why do the boiling points of halogens increase?

• Covalent bonds become stronger

• Molecules become larger

• Intermolecular forces become weaker

• Atoms become smaller

Why do simple molecular substances generally not conduct electricity?

• They have free electrons

• They lack free electrons and charged particles

• They have strong intermolecular forces

• They contain charged particles

Which of the following is a characteristic of giant covalent structures?

• Weak covalent bonds

• Ability to conduct electricity

• Regular repeating lattices

• Low melting and boiling points

What is the composition of silicon dioxide, a giant covalent structure?

• Carbon and oxygen atoms

• Silicon and oxygen atoms

• Carbon and hydrogen atoms

• Silicon and nitrogen atoms