Here are the essential concepts you must grasp in order to answer the question correctly.
Molecular Solids
Molecular solids are composed of molecules held together by intermolecular forces such as van der Waals forces, dipole-dipole interactions, or hydrogen bonds. These solids typically have low melting points and are often soft. Examples include ice (solid water) and sugar. The properties of molecular solids are largely determined by the types of molecules and the strength of the intermolecular forces.
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Ionic Solids
Ionic solids consist of positively and negatively charged ions held together by strong electrostatic forces known as ionic bonds. These solids generally have high melting and boiling points due to the strength of the ionic interactions. Common examples include sodium chloride (table salt) and magnesium oxide. Ionic solids are typically brittle and can conduct electricity when melted or dissolved in water.
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Atomic Solids
Atomic solids are composed of atoms held together by covalent bonds, metallic bonds, or van der Waals forces. They can be further classified into covalent network solids, like diamond, which have very high melting points and are hard, and metallic solids, which conduct electricity and heat well. The properties of atomic solids depend on the type of bonding and the arrangement of atoms within the solid.
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