What are materials that change color in response to temperature called?

• A. Thermochromic Materials
• B. Nanotechnology
• C. Smart materials
• D. Shape memory plastics

Answer: (A)

Thermochromic materials change color when their temperature changes. This happens because their molecular structure or crystal arrangement responds to heat in a way that shifts the wavelengths of light they absorb or reflect, producing a visible color change. The effect is usually reversible, so the color swaps back as the temperature moves back. This property is why you’ll see thermochromic indicators in temperature strips, mood rings, or novelty items where a quick visual cue of temperature is useful.

To place it in context, nanotechnology isn’t about color change itself but about manipulating materials at the nanoscale. Smart materials describe a broad category of substances that respond to various stimuli, including temperature; thermochromic materials are a specific type within that broader group that changes color with temperature. Shape memory plastics, on the other hand, change shape with temperature rather than color, so they’re not the right fit for this particular property.