Atoms, Molecules, and Compounds Quiz

Atoms, Molecules, and Compounds

• Atoms bond together to form molecules and compounds.
• Molecules are groups of two or more atoms bonded together.
• Compounds are formed when atoms of different elements bond together.
• Chemical formulas represent elements and compounds. Mixtures cannot be represented.

Learning Intentions

• Molecules consist of atoms bonded together.
• Compounds are molecules made of different elements.
• Elements and compounds have chemical formulas, unlike mixtures.

Success Criteria

• Define and provide examples of molecules, compounds, bonded atoms, molecular elements, molecular compounds and polymers.
• Explain differences between elements, molecules, compounds, and mixtures.

Glossary of Terms

• Molecule: Two or more atoms bonded together (e.g., water).
• Molecular element: A molecule with two or more atoms of the same element (e.g., oxygen).
• Compound: A substance with two or more different types of atoms bonded (e.g., water).
• Molecular compound: A molecule containing two or more different types of atoms (e.g., carbon dioxide).
• Mixture: A substance composed of two or more pure substances not chemically bonded.
• Polymer: A long-chain molecule formed by the joining of many repeating smaller molecules (monomers).
• Pure substance: Substance that contains only one type of substance (e.g., a single element or compound).

Periodic Table

• Elements are organized and presented in the Periodic Table.
• The table organizes elements based on their properties.

Molecule vs Compound

• A molecule is two or more atoms bonded together.
• A compound is a specific type of molecule, made up of two or more different types of atoms bonded together.

Two Groups of Molecules

• Molecular element: A molecule which contains two or more atoms of the same element bonded together.
• Molecular compound: A molecule that contains two or more atoms of different elements bonded together.

Molecular Elements

• Oxygen is an example of a molecular element.
• An oxygen molecule consists of two oxygen atoms joined together.
• Pure oxygen gas consists of many molecules, all alike.
• "Oxygen" can refer to either the element or the molecule.
• Check how the name is used to determine the specific meaning.

Molecular Compounds

• Molecules in compounds contain atoms from different elements.
• Carbon dioxide (CO₂) is a molecular compound with one carbon atom and two oxygen atoms.
• Water (H₂O) is a molecular compound. A water molecule has two hydrogen atoms and one oxygen atom.

Polymers

• Some compounds are individual molecules (e.g., water and carbon dioxide).
• Other compounds are long chains of atoms, called polymers (e.g., plastics, starch, proteins).
• Repeating groups of atoms form chains in polymers, like beads on a necklace.

Numbers in Chemical Formulas

• The small numbers in chemical formulas (subscripts) denote the number of atoms of each element.
• Chemical formulas show what elements make up the molecule and how many of each atom there are in a molecule.
• Water (H₂O) contains two hydrogen atoms and one oxygen atom.

Pure Substances

• Elements and compounds can be pure substances, meaning all particles are identical.
• Pure water (H₂O) contains many water molecules identical to each other.

Molecular Compounds vs Mixtures

• When sugar (C₆H₁₂O₆) is mixed with water (H₂O), two different compounds are mixed.
• The compounds are not chemically bonded because they can easily be separated.
• Mixtures cannot be described by chemical formulas.

Summary of Elements and Molecules

Remember and Understand

• Identify elements that exist as molecules (e.g., oxygen, nitrogen).
• Compare and contrast similar and different properties between molecules and compounds.
• Explain differences amongst various terms (atoms, molecules, elements, compounds, diatomic, monatomic, molecule, polymers, lattices).
• Analyze diagrams to distinguish between mixtures of compounds, mixtures of elements and pure elements.
• Identify the elements in ammonia (NH₃) and their quantities in each molecule.
• Evaluate a statement about elements and molecules.