Introduction / Context:
Understanding the hierarchy of matter—atoms, molecules, ions—is foundational for both chemistry and practical electrical topics such as materials, electrolytes, and semiconductors. A clear definition of 'molecule' avoids confusion with charged species and electron flow concepts from circuits.
Given Data / Assumptions:
- Chemical substances can be elements or compounds.
- Molecules consist of two or more atoms bonded together.
- Properties considered are macroscopic properties intrinsic to the substance (e.g., water vs hydrogen/oxygen separately).
Concept / Approach:
- A molecule is the smallest unit of a substance that retains its chemical identity and properties.
- Ions are atoms or molecules with net charge (electron deficit or excess).
- Electrical current in conductors is electron motion; atoms themselves do not 'flow' in the same sense in metallic conduction.
Step-by-Step Reasoning:
Differentiate neutral bonded units (molecules) from single atoms and ions.Recognize that options describing electron shortage/excess refer to ions, not molecules.Reject the notion of an 'atom that flows'—that is a misstatement of electron drift in conductors.
Verification / Alternative check:
Examples: H2O molecule retains properties of water; Na+ and Cl− are ions; electrons carry current in metals while copper atoms remain in a lattice.
Why Other Options Are Wrong:
- Shortage/excess of electrons: Describes cations/anions, not molecules per se.
- Atom that flows with imbalance: Mischaracterizes electron flow and current.
- None of the above: Incorrect because the correct molecule definition is provided.
Common Pitfalls:
- Confusing molecules with ions or atoms.
- Assuming electrical current implies atomic motion of the lattice.
Final Answer:
The smallest particle of a substance that retains the properties of that substance
Discussion & Comments