Allen made a diagram to compare radiation and conduction. which label belongs in the area marked y? must involve temperature differences between substances or objects occurs when molecules are in direct contact involves the movement of fluids based on density differences can occur where there is little or no matter

A label that belongs in the area marked Y must;

A. Must involve temperature differences between substances or objects

Objects that are hotter than their surrounding emit radiation which includes, but not limited to infrared light, which is also called heat radiation.

The correct answer is "Must involve temperature differences between substances or objects".

Explanation:

In conduction , there is no actual movement of matter. Heat flows from the hotter body to the colder body but when two bodies are placed in contact with each other.

In convection, there is a physical movement of matter.

Radiation is the emission of the energy. Heat travels through a vacuum in the radiation. There is no mass exchange occur. It does not rely upon the contact between hotter body and the colder body.

Therefore, the label belongs in the area marked Y is "Must involve temperature differences between substances or objects".

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.

b. a lightning bug, plug of grass, and a worm