Intermediate Quiz on Identifying Element, Molecule, and Compound

This 8- question quiz focuses on trickier examples, incorporating network solids, polyatomic molecules, larger organic compounds, and state changes (like solid vs. gas for CO₂).  

The quiz includes mixed multiple-choice (MCQ) and true/false (T/F) questions.

Recall the key definitions:

• Element: Made of only one type of atom.
• Molecule: Discrete group of ≥2 atoms covalently bonded atoms (homoatomic or heteroatomic).
• Compound: ≥2 different atoms bonded (covalent/molecular or ionic/lattice).

Instructions: For each substance, classify it as:

• Element only
• Molecule only (homoatomic/elemental)
• Molecule and compound (molecular/covalent compound)
• Compound only (typically ionic, no discrete molecules)

Some can fit more than one category depending on context (e.g., O₂ is both an element and a molecule). 

Would you like to read the comparison on — Atom, Element, Molecule, and Compound — before you begin the quiz?