Question

conduction can occur within a single substance, but parts of the substance must have which property?
different temperatures
different textures
different particle sizes
different colors

Explanation:

Conduction is the transfer of heat energy through direct contact. For conduction to occur within a single substance, there must be a temperature gradient. Heat flows from the hotter part to the colder part of the substance. Textures, particle sizes, and colors do not directly relate to the mechanism of conduction.

Answer:

different temperatures