Learn: Types of Substance

Welcome!Welcome back! You've already learned about atomic structure, the periodic table, and different types of bonding, such as ionic and covalent bonding. Today, we'll build on that knowledge by exploring types of substances and their properties. Let's get started!

What are types of substances?Substances are made up of different types of particles, such as atoms, molecules, and ions. The way these particles are bonded together determines the type of substance and its properties. Understanding these distinctions helps us explain why substances behave differently in various situations.

Molecular SubstancesMolecular substances are made of small groups of atoms that are covalently bonded. They have low melting and boiling points because the forces between molecules (called intermolecular forces) are weak. Examples include water (H2O) and oxygen (O2).

Giant Covalent StructuresUnlike molecular substances, giant covalent structures consist of a massive network of covalently bonded atoms. These substances typically have very high melting and boiling points because the covalent bonds holding the atoms together are very strong. Examples include diamond and graphite.

Metallic SubstancesMetallic substances are composed of positive metal ions surrounded by a sea of delocalised electrons. This structure allows metals to conduct electricity and heat, while also making them malleable and ductile. Examples include copper and aluminium.

Ionic SubstancesIonic substances are formed from positive and negative ions held together by strong electrostatic forces called ionic bonds. They usually have high melting and boiling points and conduct electricity when molten or dissolved in water, as the ions are free to move. An example is sodium chloride (NaCl).

Comparing Types of SubstanceEach type of substance has different properties based on its bonding. Molecular substances have low melting points, while giant covalent structures and ionic substances have high melting points. Metallic substances are special because they conduct electricity and are malleable.

Review Time!Great work! You've learned about types of substance, including molecular, ionic, metallic, and giant covalent structures. Let's test your understanding of these key concepts.

Well Done!You've completed the lesson on types of substance. Keep practising to strengthen your understanding of these important concepts!