NIC Cosmetology Written (Theory) ExamScientific ConceptsMedium
A cosmetologist is discussing the different forms of matter with a client. They mention that a substance can exist as a solid, liquid, or gas, depending on its temperature and pressure. What fundamental concept of chemistry is being described?
- AStates of matter
- BPhysical change
- CChemical change
- DChemical reaction
Show answer & explanationAnswer & explanation
Correct answer: A. States of matter
The description of a substance existing as a solid, liquid, or gas directly refers to the three fundamental states of matter, which are determined by the arrangement and energy of their particles.
Why the other options are wrong
- B. A physical change alters the form or appearance of a substance but not its chemical composition (e.g., melting ice). While changing states is a physical change, 'states of matter' is the more direct and fundamental concept being described.
- C. A chemical change results in a new substance with different properties (e.g., burning wood).
- D. A chemical reaction involves the rearrangement of atoms and molecules to form new substances.
States of Matter
The distinct forms that matter can take, primarily solid, liquid, and gas, characterized by differences in particle arrangement, energy, and intermolecular forces.
- Solid: fixed shape and volume, particles tightly packed
- Liquid: fixed volume, takes shape of container, particles close but mobile
- Gas: no fixed shape or volume, particles widely dispersed and energetic
- Transitions between states are physical changes
Memory trick: Matter's Many Manifestations